Using sites like SEOProfiler and MagesticSEO, I've found about 10,000 links to my homepage with anchor text ranging from "generic viagra" to "nike shoes". This timeframe precedes my SERP drop from page one to somewhere down in the pits of hell. However, WMT only shows a few hundred IBLs, and they're all relevant.

Does Google only "rate" me on the IBLs that they're showing? If so, why did I drop so suddenly?

Thanks, this is giving me a headache.