Right here:
http://www.tqitfanpatch.com/
If you look in the older sections of this forum (up in the stickies) you can read about all the problems with rubber banding and all sorts of horrors. As soon as I installed IT, I installed the fan patch and I have had few problems as described in these threads. It makes the game, if not perfect, but playable.
I would suggest reading over all the stuff fixed in the FAQ in the patch information section. The guys responsible have done a whole lot of work on this thing. They deserve a big thank you from all of us.
Regards,
bginer