last month, my site fell from #4 on google (for my favorite-est keyword) all the way down to the pits of hell. I can rank for internal pages, but my home page is gone. I used a couple of ibl checkers and found over ten thousand links to my domain with such unrelated phrases as "generic viagra" and "women's nike shoes". I understand that bad links aren't supposed to de-rank (is that a word?) a site, but the timing sure seems like it did. should I continue trying to clean it up or just get a new domain and redirect?