My 2nd Adwords account went into manual review a few weeks ago. I finally got it back last week.
But, the amount of traffic my old campaigns were getting was pathetic. Only a few hundred impressions and 1 click here and there.
I then duplicated those campaigns. They received more impressions and more clicks, but it was still so freakin low compared to the traffic I received before the damn review.
Any ideas on why this is happening?
Competition and placements...
Your account may be flagged on their back end so pubs that dont want to display "flagged" accounts no longer show your ads.
arrgg cant edit post... above is pure speculation based on how other ad networks work
Agreed. They are throttling you unfortunately 
My account got reviewed last week and traffic slowed down for about 3 days following the review before returning to normal. Try raising your bids and see if traffic restarts, then lowering them back down to where they were before. This was just for my content network campaigns.