As someone who has both versions, there are some differences, but probably nothing major. You're right, the track listings and timings don't help much. Apart from the 'Man on Fire' and 'Aliens' cues, the PonyTail version includes the unused 'Roy Rogers meets Beethoven's Ninth', and the second track ('The Terrorists') has a short excerpt from 'Singin' In The Rain'. This is not heard in the film, but appears on the track at the point where the computer expert (I forget the character name) disables the elevators. With these two exceptions, the rest of the PonyTail release plays pretty much as heard in the film. The Varese Sarabande version includes more unused cues (like the instrumental 'Let It Snow...'), or extended versions of the score that were chopped and changed for the film itself. The running time for the Varese Sarabande indicates a running time of 77 mins, and the PonyTail at 51 mins. If you had both editions and a bit of patience, you could probably piece together a 'definitive edition' of your own, though sadly without Run DMC's song from the credits. Hope this is of some help.

bentleyjames52, April 13, 2005; 9:40 PM