Google´s cache of your homepage shows it was crawled february 14, and the "text only" version is not as bad as it could be infered by what other posters above say about your code. Google doesn´t even have a "DOCTYPE!" declaration and if you validate their search page it retrieves a lot of errors.
I think that if you have done well so far with that site, as is, that is not the problem and surely a lot of inbound links at once can cause you a flux, like if google had to "evaluate" what went on. How long since this has happened? Also, contextual words next to the anchor text -link- to your page at those forum pages matter, they give google some context... perhaps you have "disoriented" google with all that overload of contextual data to analyze and it takes some time to assess all the info (give it two weeks at least).
Also, you say "too much links"... how much is "too much"? 20, 100, 500? I don´t think you have to reach 10k links to be penalized, because only few people on the planet would be able to add 10k inboud links at once. I think that penalization or temporary ban can be achieved if it detects more than 50 links at once (something feasable for a normal
SEO optimizer in a day). They try to rule for the majority of cases, not for exceptions, so if they would wait for youto add 10k links, there would surely penalize no-one, ti would be useless for daily maintainance of their result´s pages.
My two coins. Good luck