Philadelphia ? Something wasn’t quite right with Bill Cosby.

It happened just over a month ago, during his first five minutes on a concert stage in Austin, Tex. The audience fidgeted nervously as Cosby awkwardly stumbled over his attempted punchlines.

A critic for the Austin American Statesman wrote that Cosby “took his seat at center stage, and for the first five minutes struggled and sputtered.” He said the comedian “talked, backtracked, stuttered. It was an odd moment …”

Still, it wasn’t quite as odd as the revelation in the Philadelphia Daily News that Cosby allegedly had accused a longtime friend of witchcraft before he evicted her as overseer of his estate in Elkins Park, Pa., where she’s lived for 19 years.

Cosby’s strange behavior, in which he and a spiritual adviser, billed as a “lama,” accused Gladys Rodgers of using blood and “sparkles” in witchcraft rituals, was the talk of radio and tabloid television this week. The sparkles are bits of mica, a shiny material in the soil in this area.

But some family members and friends have been increasingly worried about the comedian’s behavior since his only son, Ennis, was murdered in a freeway robbery in Los Angeles in 1997.

Thornhill Cosby, the entertainer’s uncle who once headed the Philadelphia NAACP, said Cosby had been increasingly distant from his relatives here since then.

“I don’t know whether the Ennis thing has turned him around I don’t know what’s happened to him,” Thornhill Cosby said. “We’ve lost contact with him.”

The Philadelphia-born Cosby, still an icon of American comedy, will turn 65 this month. He shows no interest in retirement as he jets across the country for speeches, charitable gigs and occasional concerts. It would be easy to blame some of his recent stumbles on exhaustion and advancing age.

And life has never been as easy as the sweater-clad, “national dad” of the “Cosby Show” made it look at times. He shattered racial barriers in the 1960s by appearing on TV’s “I Spy” and ruled the airwaves during the 1980s as Cliff Huxtable. But Cosby faltered during the 1970s, when he had trouble finding roles and later admitted he had been unfaithful to his wife, Camille.

But it’s becoming painfully clear that the last five years have been the most difficult of Cosby’s storybook career.

In January 1997, 27-year-old Ennis Cosby was shot and killed on the side of a freeway when he stopped his Mercedes-Benz to change a tire. A Ukrainian immigrant, who later admitted that the young Cosby was “a target of opportunity” for a robbery, is serving a life sentence without parole in California.

Gladys Rodgers, the ex-wife of Philadelphia basketball legend Guy Rodgers, has told the Daily News she started seeing changes in Cosby around the time Ennis died.

Rodgers said that was when an Englishman named David Kirby, Cosby’s spiritual adviser, became part of the comedian’s inner circle. She said Kirby had used fire, dice, seeds and beads to do “readings” while wearing a “gorgeous purple-and-white striped (gown) with an amulet around his neck.”

She said it was Kirby who eventually accused her of witchcraft and asked her to leave the Cosby mansion last month after an investigation that included “a ritual of fire,” rolling dice, and analyzing floor sweepings.

It’s hard to know what to make of the accusations. Cosby’s longtime spokesman, David Brokow, had no comment for this story.