Guessing wrong, I have only one hard drive installed at the moment so OS, page file, and all trainz versions are on C:\. What would help, you guys getting this problem try installing a new version of TS2010 in a different folder, patch that to 44088. Copy that entire folder to a backup, then copy the UserData folder from your faulty 49933 folder to the 44088 folder. Now check to see if you get the same problem in 44088, if you do that confirms the problem is a faulty asset rather than the patch, if you don't then the most likely problem is some asset that works okay in 44088 but something in 49933 doesn't like that asset.
Dick, you got a probable culprit as to the faulty commodity?