Tomb Raider 1 runs fine with Glidos on my PC; but I can't get Unfinished Business to do the same!

At first, I got a message about needing a CD, so I removed the line about the CDCheck in the configuration file, (read that on this site). After that, when Glidos would begin to run Unfinished Business, I'd see the various company logo screens, and then the game screen. When I chose "New Game", the window would close.

I'm wondering if I don't have the right version of Unfinished Business, or if I'm just really stupid about installing it. The name of the file I downloaded is 3Dfx Tombub.exe {847 kb}, which was under a section specifically for use with Glidos. I extracted the file and put it in the Tombraid folder. I also tried using the installer, but all that did was replace the necessary Tombraider application with the one from the CD.

Can someone help me with this?

Okay, read the guidelines, so here's all the extra info I could find in my comp:

Intel(R) Pentium(R) (M)
processor 1.70GHz
512 MB of RAM
Windows XP
Using Glide
VDM Sound
Resolutions: 640 x 480
800 x 600
1280 x 1024
(tried all the above res)
I HAVE read the README