In the first U.S. Lara Croft Tomb Raider: Cradle of Life TV ads, there was an ultra pop song playing very faintly in the background (horribly muddy sound in this ad for some reason) with actual lyrics of 'la la la' - closest thing I could relate it to is The Dickies cover of the Banana Splits theme song.
False leads already discounted: definately NOT Prodigy - smack my bitch up. Nor is it Pink - feel good time. It's nothing on the soundtrack either.
There's no way to e-mail Paramount directly to ask them, and I've scoured the web trying to find this out to no avail. With the commercial out of circulation I fear this is a lost cause...