Doom 3 : RoE -- I need tech help!

I really hope someone here can help me with this...


Okay, so... I've installed Doom 3 and Doom 3 : RoE as well as updated to v1.3.1 and Doom 3 works PERFECTLY fine. Doom 3 : RoE, however... I can get to the main menu just fine. When I go to create a new game, it shows the "loading" text with a bar under it. It loads to about 5 ~ 10% and then it sends me immediately back to the main menu.

I've tried reinstalling, but no cake. The only resolution I found on the internet was were someone just bought a brand new copy and it worked. I really don't want to do that and I really do not think there's anything wrong with my current copy.

If anyone knows what's going on, I would greatly appreciate your help.

all i can think of is that the there's some minute difference in the installer between doom 3 and the expansion and maybe running a newer operating system mixed with that could cause the code fairy to come and pineapple something up. what's your operating system? i know i've got doom 3 and resurrection of evil in the garage somewhere, i'll see if i can get it to work on my notebook

Windows 7 Ultimate 32-bit