Or just state that zero feedback bidders either 
A) are not welcome or B) have to contact you 
first or you will cancel their bids. Then just 
cancel the bids of any zero feedbacker who bids 
without contacting you. (And add them to your 
blacklist since they apparently didn't read your 
auction description.) It's a bit of a pain, but 
then you don't need to worry about it.

And welcome back!!!!! ^_^

Many Sharp Smiles,
--Drac