JJ.
Try these:
1...Have you got the FVR V8 mod, WTCC11 mod, ADAC mod or Honda Civic cup? These share model ID's with this mod, but from my experience all the model ID does if its clashing is cause online issues in multiplayer, single player still works
2...The Class ID is 119 but I can't find anything that clashes with that, but there maybe a mod out there with the same class ID, this may stop the game working.
3...Like what Jempy asks, have you got the GT Power expansion?
4...Is the game the Offline or Online version? I'm not sure what the difference is, but I guess the offline version has different a folder structure which would cause this mod not to work, I think.
5...The SRM program, run it and just next to where it says "select" theres a + and - click the "+" and select Race 07, for the game name just write anything like "Race" then click "browse" next to where it says tracks folder, once it opens a new box go into the directory for race 07 and select "Race_Steam.exe", click ok then click Validate, then it should list all the mods and tracks in which you can the select or deselect by either placing or removing the tick befored each mod/track, all this does is place the mod away from the race 07 mod directory and when you tick the box it places it back in the mod directory.