"The people who say this haven't apparently been listening to me," the likely Democratic presidential nominee said in response to a question at a town-hall style event.

Obama blamed criticism from "my friends on the left" and "some of the media" in part on cynicism that ascribes political motives for every move candidates make. "You're not going to agree with me on 100 percent of what I think, but don't assume that if I don't agree with you on something that it must be because I'm doing that politically," he said. "I may just disagree with you."

The Illinois senator was responding to a question from a self-described "reformed Republican" who said he worked for Democrat Bobby Kennedy four decades ago and thanked Obama for restoring "that faith."

"You had an interesting week of being accused of flip-flopping, which is mostly nonsense," the man said. He then asked Obama to restate his Iraq position, and Obama used the opportunity to dispel the idea he had generally changed his stances.

Since wrapping up the Democratic nomination last month, Obama has voiced positions that break with the Democratic Party's left and seem to shade his own past positions on a range of subjects. He's drawn criticism from some liberal Democrats who question his loyalty and from Republicans who accuse him of flip-flopping.

His remarks aside, Obama is clearly competing for the center of the electorate. Originally best known as an anti-Iraq war candidate, his general election commercials appear nonpartisan and make an obvious play for voters across the political spectrum by focusing on family values and patriotism as well as "welfare to work" and lower taxes.

Over the past few weeks, he angered liberals by supporting compromise electronic surveillance rules for the government's wiretapping program even though the bill provided immunity that he opposed last year for telecommunications companies that conducted warrantless eavesdropping. When the Supreme Court overturned the District of Columbia's gun ban, he said he favors both an individual's right to bear firearms and a government's right to regulate them.

And, he broke with death penalty opponents when he disagreed with the Supreme Court's decision outlawing executions of people who rape children.

A federal appeals court on Tuesday put off deciding on the wireless industry's challenge to the regulations until the Federal Communications Commission gets preliminary clearance for the rules.

After a panel of experts appointed by the FCC pointed out that many cell towers along the Gulf Coast stopped working when they lost power during Hurricane Katrina, the agency proposed in May 2007 that all cell towers have a minimum of eight hours of backup power that would switch on in the event a tower lost its regular energy source.

The loss of power contributed to communication breakdowns that complicated rescue and recovery efforts during the 2005 disaster.

Wireless companies have said the regulations were illegally drafted and would present a huge economic and bureaucratic burden. In particular, they said, the thousands of generators or battery packs required would be expensive and local zoning rules or structural limitations could make installation impossible in some places.

The FCC agreed in October to exempt cell sites that a wireless carrier proved couldn't meet the rules. The FCC would give companies six months to report on the feasibility of installing backup power and another six months either to bring sites into compliance or explain how they would provide backup service through other means, such as portable cellular transmitters.

CTIA-The Wireless Association, Sprint Nextel Corp. and others asked the U.S. Court of Appeals in Washington, D.C., this year to intervene, saying the exemptions would still leave wireless companies scrambling to inspect and compile reports on thousands of towers.

The appeals court put the rules on hold while it heard each sides' arguments in May.

Five men charged in the Sept. 11 attacks, including alleged mastermind Khalid Sheikh Mohammed, are to appear Wednesday and Thursday for pretrial hearings in the Bush administration's special tribunal for terrorism suspects. Their trials have not yet been scheduled.

The suspects could get the death penalty if convicted of charges that include murder.

A judge is expected to hold hearings to explore defense allegations that Mohammed intimidated his co-defendants into refusing military lawyers.

Meanwhile, a judge in Washington is considering a challenge that could disrupt the first scheduled war crimes trial, on July 21, of Salim Hamdan, a former driver for Osama bin Laden.

Hamdan's lawyers say a recent Supreme Court decision has raised new legal issues that require U.S. District Judge James Robertson to delay the trial. The government says it wants to move forward.

Robertson has scheduled a July 17 hearing in Washington on the issue, just four days before Hamdan is to go on trial in a specially built courtroom on a former airstrip at the U.S. Navy base in Cuba.

A ruling in favor of the prisoner could also delay the trials for other men held at Guantanamo, and perhaps force the military to devise a whole new way to prosecute alleged terrorists.

The vote, planned for Wednesday, would end almost a year of wrangling between the House and Senate, Democrats and Republicans, and Congress and the White House over the president's warrantless wiretapping program that was initiated after the Sept. 11, 2001, terrorist attacks.

A major issue was the Bush administration's insistence that the bill shield from civil lawsuits telecommunications companies that helped the government eavesdrop on Americans without court permission after 9/11.

The White House had threatened to veto the bill unless it immunized companies like AT&T Inc. and Verizon Communications Inc. from wiretapping lawsuits. About 40 such lawsuits have been filed. They are all pending before a single federal court.

CBS Corp.'s CBS Broadcasting subsidiary, News Corp.'s Fox network and other major network affiliate groups sued EchoStar 10 years ago in South Florida to prevent the Englewood, Co.-based company, which operates the DISH satellite network, from providing distant network signals to customers who can receive local affiliates' broadcasts through regular antennas.

The Satellite Home Viewer Act of 1988 allowed carriers such as EchoStar to provide secondary transmissions of copyrighted distant network programming to "unserved households," those that could not otherwise receive the signals.

The lawsuit claimed that EchoStar was infringing on network copyrights by providing the signals to "served" households as well.

After a two-week bench trial in 2003, the district court found that EchoStar retransmitted network programs to hundreds of thousands of served homes, which it called "willful or repeated" copyright infringement. That ruling was upheld by the 11th U.S. Circuit Court of Appeals, and the U.S. Supreme Court declined to consider an appeal in January 2007.

According to court documents, EchoStar complied with an injunction that went into effect Dec. 1, 2006, by disconnecting distant network channels to about 900,000 customers — at a loss of $25 million a year.

Tuesday's hearing is the first hearing since the Supreme Court ruled last month that detainees can challenge their imprisonment in civilian courts. Officials are expecting hundreds of lawyers and spectators to attend.

Judges will eventually review the government's evidence and decide whether detainees are being lawfully imprisoned. The key issue Tuesday is when that review will begin.

The Justice Department proposes eight weeks to begin filing the evidence. Lawyers for the detainees say it should be faster.