Buffy-less UPN is raising its comedy stakes this fall. The little network that couldn't climb out of last place this season is adding four comedies to its lineup, three of which will air as part of a new Tuesday sitcom block. The goal: To stem a steep 17 percent ratings slide brought on by a slumping Enterprise and poorly performing dramas (buh-bye Platinum, Twilight Zone and Haunted), and to better capitalize on its one real success story its Monday laffers. Here's a night-by-night analysis of UPN's new lineup:Monday UPN isn't about to mess with a good thing, so it's leaving this night mostly intact. The Parkers will continue to kick things off at 8 pm, followed by the new twentysomething comedy The Opposite Sex, starring hip-hopper Eve. (It replaces One on One, which moves to Tuesday.) Some of Sex's raunchy gags had folks visibly shifting in their seats at the network's Upfront presentation Thursday. In one highlight clip, the back of Eve's too-tight dress gets caught in a man's zipper. (Tasteless innuendo on UPN? Impossible!) Girlfriends and Half and Half are staying put at 9 and 9:30 respectively. Tuesday With Buffy history and hit dramas scarce, UPN is wisely playing for laughs on Tuesdays and taking on NBC and ABC's comedy blocks in the process. Monday transplant One on One will lead off the night at 8 pm, followed by the network's most buzzed-about new entry, All of Us. Based on the "domestic adventures" of Will and Jada Pinkett Smith (who serve as producers), the series stars Duane Martin (Deliver Us from Eva) and Elise Neal (The Hughleys). Anchoring the 9 pm slot is Rock Me Baby, starring Dan Cortese as a radio shock jock who's tamed by his new baby. The crowd was underwhelmed by the Veronica's Closet alum's latest gig, but broke into guffaws at the mere title of its 9:30 follow-up, The Mullets, a blue-collar comedy about two down-on-their luck brothers (Michael Weaver and Six Feet Under's David Hornsby, who sport identical hairdon'ts. Loni Anderson adds some va-va-voom to the mix as their "still sexy" mom. WednesdayEnterprise remains at 8 pm, but UPN is hoping the show's bold new direction will convince Star Trek fans to give the ailing prequel series another chance. (From what we've seen, they'll blow stuff up more often, and Jolene Blalock's T'Pol will show more skin and make out with Scott Bakula's Capt. Archer!) In Twilight Zone's place at 9 pm, the network has sloted Jake 2.0, a new sci-fi series about a National Security agent (Felicity's Christopher Gorham) who possesses super-human powers. His first mission promises to be a doozy, though: Convincing viewers that his show is a decent alternative to the WB's brilliant Angel, which is poised for a big comeback next season. Thursday Big talk and even bigger body slams will rule the night as WWE! Smackdown returns for its fifth season. At the presentation, a UPN sales honcho was hoisted up by a musclebound wrestler and carried offstage like a sack of potatoes. If only all TV network execs were so easily managed! Friday UPN will continue to play it safe on Fridays with the return of movie night. Among next season's big titles: Ready to Rumble, Angel Eyes, The Tailor of Panama, Novocaine, Species 2, The Astronaut's Wife and Lost Souls. Er, as you can see, the network is using the term "big" rather loosely here.