Feisty's kernel has been updated to 2.6.20-16. This new kernel has the TIFM drivers v. 0.8, which is the same version my script would install. As such, if you are up to date with all kernel updates (use
uname -r to see what you're using), the script will make no change to your performance. If it doesn't work with the script or if it doesn't work with the updated kernel, it is probably an upstream bug in the driver.