I see that you have been around a while so my initial question is mute. Has it ever worked, or did this just happen? After I rooted with Frayo, I had to use file to fix this problem and when I rooted GB I believe a file was included in that to fix the problem but I just read that section and do not see the file listed. You might go over there and look around. http://www.toms-world.org/android/
I erased the original file from my sd card and can not remember the name. I had something to do with going from RFS to EXtT4 file system.