If it weren't for the incessantly loquacious computer onboard the medical rescue vessel in the new terror-in-space flick "Supernova" -- a 1-900-voiced, femme fatale HAL that never shuts up for two minutes together -- this might not be a bad movie. I mean, for a picture MGM was too chicken to screen in advance for critics.

In fact, it's not even a horror movie, really -- even though that's how it's being marketed.

"Supernova" is a victim of "Sphere" syndrome, that terminal disease suffered by producers and directors who think if they can just get respectable, intelligent actors to star in their cheap sci-fi flick, the movie will instantly become something better than it is.

Director Thomas Lee (a pseudonym for the embarrassed Walter Hill) didn't have the budget to lure Dustin Hoffman, Samuel L. Jackson or Sharon Stone (and besides, they've probably learned their lesson), so he went for second-tier smart set players James Spader ("Crash") and Angela Bassett ("How Stella Got Her Groove Back") -- who are largely wasted on this predictable, adrenaline-free, F/X spectacular.

The plot: Space ambulance Nightingale 229 dimension-jumps to a rogue moon from which the crew received a distress call and picks up a survivor (Peter Facinelli, "Can't Hardly Wait"), who brings on board a mysterious object that looks like a lava lamp cross-breeded with one of those plasma globes from a 1990 Sharper Image catalog.

Handsome Facinelli sports a diabolical smirk and acts suspicious, but none of the crew (Spader, Bassett, Lou Diamond Philips, Robin Tunney, Wilson Cruz) bother to keep an eye on him as they repair damage accrued to the ship in the dimension leap, and the next thing you know, he's killing folks with the super-human strength he's gleaned from his alien pet rock.

That's about it.

I admire Hill for taking the high road and the dry road (the movie isn't half as bloody as its brethren "Alien" movies or the disgusting "Event Horizon"). He's trying to make a scary space movie without resorting to cheap, Wes Craven tactics. The ship even has adequate corridor lighting!

The problem is, he fails. "Supernova" is boring.

Being inherently interesting, intense and talented actors, Spader and Bassett do what they can to flesh out their action figure characters (although they're left largely to their own devices), and the director does take a feeble shot at character development when he's not busy shooting PG-13 sex scenes (the cast pairs off in the first reel), planting fascist future clichés (procreation is government-regulated) and defying common sense and the laws of physics.

But even when the story edges toward becoming stimulating, there's that damn computer cooing "Warning!" and "Attention!" every 20 seconds. Enough already!

Even if it isn't as terrible as the studio obviously thinks it was, sneaking it into theaters like they did, "Supernova" is just further evidence that the space-scare flick is a zombie genre, long-dead but still plodding around in advanced states of decay. And there seems to be no end in sight -- three more movies a lot like this one ("Pitch Black," "Mission To Mars" and "Red Planet") are opening in the next few months.