I had same problem with newest Logitech's driver Logitech Gaming Software 32-bit v5.08.146 (2009-09-16).
But older version Logitech Gaming Software 32-bit v5.00.182 (2005-04-28) is working properly, please install this.
But I have question about wheel turn degrees. Is it possible to made automatic degrees settings for G25 depend by selected car in LFS? If I choice the UF1, then wheel should set to 720 degrees. If I choice the MRT, the wheel should set the 270 degrees automatically. It is not working, then I do it manually in Logitech Profiler (outside/exit LFS and set it in Windows), but can be automatized it? There is "Wheel Turn degrees" setting slider in Options->Control, but it is never work. I heard that this should to work automatically with G25 (without scripting in LFS), how it is can make to working?