this makes me a little braver to update mine to 3.5.2 as well.
Well I updated to 3.5.2 over 36 hours ago.
So far no problems, and 3.5.2 seems to be running just fine -
all my add-ons still work (I checked updates for those to confirm too).
I am getting used to having to invoke IE Tab, or even IE separately when facing any compatibility issues.