I use Ubuntu 10.04 as well. I have both setups on my computer, Linux v0.5.4b1 (combined with most parts from the v0.6.5.5 version), as well as Windows v0.8.8.1 running well through Wine. Also, I have Racer Linux setup on the another computer with Edubuntu, used by my preschool boy. On my computer, I use Linux as a non-cg Racer version, and Windows/Wine version as a cg. I would definitely recommend KS95 advice and use Racer v0.8.8 (or higher) through Wine. If your hardware cannot support cg version of Racer, and you still want to use Linux to run the Racer, there are few things you need to do.
First, Linux is CASE sensitive, so all the car and track file names have to be in lower case in order for Linux Racer to recognize it. Also, there should be no spaces in the files name, just use _ to separate words. This is also recommended for all other names inside car/track file.
Second, everything inside car/track files should be in lower case too. Some car/track files are already like that so they have no problems. Otherwise, if some of the file content is not in the lower case, then there will be problems as you described it. There is lowerize toll in Linux Racer that I never managed to get going. I use following method. Open the car or track file in terminal and use this command line to make everything inside lower case: for i in `find * -depth`; do (mv $i `echo $i | sed 's%[^/][^/]*$%%'``echo $i | sed 's!.*/!!' | tr [:upper:] [:lower:]`); done
Third, for a car file you would want to make contents of car.ini, car.shd and views.ini all in the lower case. I use gedit to open them (make sure that permission is set not to execute when opening in gedit). Gedit has nice plugin in preferences "Change Case" that you can activate and use to make everything lower case inside these three files. For car.shd and views.ini, after you open it in gedit, you can just select all and make everything lower case. For car.ini file, I would recommend to select text after the name of the car and other comments (after where it says wheels=4).
For track files, you would want to make contents of track.ini and track.shd all in the lower case.
If this sounds like a lot of hassle, it is. While you can get Linux to run lovely a native non-cg Racer, I still say: just use Wine. You can also try some of the older Windows non-cg version (last one was v0.6.5.5) through Wine. If you want to use latest non-cg versions, v0.8.10 - v0.8.12, you have to start them with racer_nocg.exe
