##You weren't suspended, you just don't have enough reputation to review posts. If you visit askubuntu.com/review you will see:
There was a recent change, raising the rep requirement to review from 125 to 500; hence the reason you could review yesterday and not today. For more information on the change see http://meta.stackoverflow.com/questions/186373/propose-a-privilege-to-sit-in-the-500-reputation-mark/
I personally think this was an awful change....
##On the review audit subject..
You do get a notification if you have been banned from review, on sites where review audits are enabled. Audit aren't actually enabled on Ask Ubuntu. You also get a message for each passed and failed review audit.