Okay, here's the deal. I know, without a doubt, that summer is on the way. It has nothing to do with the NBA playoffs or the fact that I'm treating a hay fever case at least three times a day. I know it because I gave my first tetanus shot of the season today. 11-year-old Benny Rackshow hobbled into the office today with his mom, his foot gushing platelets like a shook-up Coke bottle. He'd been playing "Ninja Delivery Boy" out back in his barefeet and landed on a rusty nail. Without fail, when barefoot boys start showing up in my office on the verge of lockjaw, you can rest assured that the calendar says May.

Another reason I know that summer is on the way, is the fact that the big bankable movie stars are starting to show up in my theater again. After spending the spring with the likes of Howard Stern, Billy Bob Thornton, and the cast of "Friends", I can sense that summer is here 'cause Ivan Reitman has teamed up with Robin Williams and Billy Crystal in a big-budget comedy called Fathers' Day.

All that certainty had me feeling pretty good as I walked up to the ticket window. With Williams and Crystal, this thing had two of today's top comedy stars in a remake of a successful French film (1984's Les Comperes). The formula that made The Birdcage such a smash was up for grabs and the Ghostbusters auteur took it. He brought in scripting sparklers Lowell Ganz and Babaloo Mandel (City Slickers, Splash) to add the requisite American punch, and got Warner Brothers to hold a spot for it in their pre-summer rotation. A sure thing, for sure.

Maybe all that certainty is where things went awry. It's one of those deals, like a college football game, where the championship team struts onto their home field with a starting roster of All-American seniors and a 30-point spread, yet when the clock reads 00:00, Notre Dame has up and lost to Slippery Rock. Maybe with Fathers' Day, the principals knew they had a sure thing, and forgot to play the game with intensity.

The dreadful undercurrent of this film is the feeling that we've seen it all before. Maybe what started out as certainty took a left turn into predictability. There's nothing fresh or surprising about the premise -- two mismatched characters chase after the boy who could be their son, encountering comedic missteps along the way. Even Williams and Crystal, who have delivered so many inspired moments in features past, seem to be trudging through the motions, giving us their off-the-rack schtick. Williams trots out his stock company of multiple personalities as the needy headcase and Crystal revisits his oft seen world-weary yuppie in search of an emotional side. (By the way, the combo of headcase and professional worked much better in What About Bob?) I'll admit there's an occasional chuckle to be had during the screening, but it only points up the fact that there's a heck of a lot of dull stuff here. Even the promise offered by Nastassja Kinski's and Julia Louis-Dreyfus' names in the opening credits is a disappointment, as each is limited to a scant few minutes of do-nothing screentime.

The plotline asks us to forgive a load of unlikely happenstance and coincidence, and we're sold out on limp bathroom humor and "Three's Company"-type slapstick. There are mistaken identities, grunge bands, sleazy drug dealers, flat tires, redneck truckers, and slot machines. Seen any of those before? And worst of all...in an odd attempt at physical humor from Billy Crystal, we're forced to accept The Headbutt as a plot device.

In short, if you want something certain, stay home from Fathers' Day, slip off your shoes and dance around at a construction site. You can save the money from your movie ticket and buy a sure-fire tetanus shot.