The 1.1 final patch has been pulled from download now.
It was apparently buggy with the biggest failing being that the Bf 109-K rudder was disabled!
UBI are saying that it was the wrong patch mistakenly released and have promised a proper working patch next week.
If you have upgraded the only way to get back to 1.1b (apparently), is to do a full re-install.
If you haven't installed the patch then I personally wouldn't bother trying to get hold of it unless you're desperate to get into a game with someone who has patched.
I have patched up to 1.1 and for that sake of a week I'm not doing a re-install, unless it takes longer to get a decent patch or I can't get a game with the version I'm on now.
The choice, gentlemen, is yours!