I have not checked Google Webmaster Tools for months now. But I have just gone in now to look at my backlinks and it says I only have one back now from one site. Last time I looked I had links from over a hundred sites. The site still has a page rank of 3 though.
12 Feb 13 7:15 pm
I had this happen a little over a year ago and don't know what is was but I think a couple weeks went by and things suddenly were back to the way they were, I probably wouldn't worry about it too much.