"The 40-Year-Old Virgin,", remained the No. 1 movie with $16.4 million, a strong hold from its opening weekend, according to studio estimates Sunday.
Terry Gilliam's "The Brothers Grimm," a fantasy starring Matt Damon and Heath Ledger as the 19th century fairy-tale siblings, debuted in second place with $15.1 million.
"The Cave," an underground monster movie featuring Morris Chestnut, Piper Perabo and Cole Hauser, opened weakly at No. 6 with $6.2 million.
The weekend's other new wide release — the romance "Undiscovered," featuring Ashlee Simpson and Pell James as gal pals who fabricate media buzz to help a friend's music career — flopped with just $690,000, finishing far out of the top 10.
A movie slump continued, with the top 12 films taking in $82.8 million, down 2.5 percent from the same weekend last year. Hollywood is having its worst year since the late 1990s, with summer attendance expected to come in 12 percent behind 2004's, according to box-office tracker Exhibitor Relations.
There have been bright spots amid the slump, notably the racy R-rated comedies "The 40-Year-Old Virgin" and "Wedding Crashers," which are holding well on the strength of good reviews and word of mouth.