One thing I noticed when trying to get the modded versions to work that may be causing strange errors for people is that unless you use your compression program to extract the game (or you know where all the files should be located), you may not have the files extracted to the proper locations. This is a common problem with a simple solution that's easily overlooked.
Here's an example...I currently use WinZip at my workstation (I play the game on my work PC...). Normally, I just select all the files in an archive, then click and drag them where I need them to go (in a directory on my Desktop, for example). If you do that with the OGG version of WW1M, then the files won't be placed in the proper "art" and "sound" directories; the result is that you'll return some weird errors and the game crashes before it starts. The only thing that clued me in to this was that I had my original installation of the game still on my PC and I checked the directory structure.
So I entered the desired directory into WinZip, let it do the extraction of files itself, and everything was where it should have been placed. More importantly, the game WORKED, which was what I wanted anyway.
--SMR