I haven't out ow to jump in the game (deus ex), but I did find this on Gamebanshee. Here's their advice:
Before we begin, be sure you're playing with the latest patch, version 1112mf, which is an approximate 37mb download. If you have the Game of the Year edition, you're either there or at 1109f, in which case you'd only need the 1109 to 1112mf 4.5mb patch, which is a little more difficult to find. The good thing is that the standalone 1112mf (multiplayer/single player) patch will upgrade any version, so download that if you're unsure.
As for jumping in this game (deus ex), I'v found this site:http://strategywiki.org/wiki/Deus_Ex/Controls
Jump seems to be done this way:
Hit the spacebar, then hit insert or hit the spacebar and the insert key at once.
Hope this helps