As this weekend's box office results soberly showed, this summer's much-ballyhooed sequels to "Legally Blonde" and "Charlie's Angels" will be lucky if they make it to the $100 million mark.

So far, "Charlie's Angels: Full Throttle" has taken in $82 million -- not enough to cover its $144 million production costs (that's not counting what it also took to market it) -- and "Legally Blonde 2: Red, White & Blonde" has pulled in $63 million, the Los Angeles Times reports.

Other sequels delivering smaller-than-expected returns this year have been "2 Fast 2 Furious" (with $122 million) and "Terminator 3: Rise of the Machines" ($110 million), not to mention the outright duds "Rugrats Go Wild!" ($37 million) and "Dumb and Dumberer: When Harry Met Lloyd" ($25 million).

And while the situation is not enough to slam the brakes on a "Charlie's Angels 3" or yet another "Fast and the Furious," corporate Hollywood is noticing that audiences won't automatically flock to empty-headed movie franchises.

"If there was any hubris or arrogance to the industry's approach, it's that we got accustomed to believing 'build it and they'll come,' " Marc Shmuger, vice chairman of Universal Pictures, tells the Times. "What we've seen this summer is that movie audiences are declaring their independence of thought."

Sony executives tell the paper that the strong foreign ticket sales for "Angels" -- which stars Drew Barrymore, Cameron Diaz and Lucy Liu -- may yet save the picture and may even justify another installment.

"It's too early to tell," said Amy Pascal, chairman of Sony's Columbia Pictures. "I'm watching closely and hoping it will make sense."

For the record, the summer's successful sequels have been "The Matrix Reloaded" ($274 million) and "X2: X-Men United" ($213 million.) "Bad Boys II" opens Friday.