Supplementals - caused by changing anchor links?

That is - regarding keywords for ranking pages in serps?

[sandpetra]

I just noticed something on a forum i have no control over.

It appears that the page in question with a link to me has gone supplemental after a quick keyword search - only, I assume because my signature links changed the anchor text link some time ago.

The page in question should not really rank for the term I am interested in - as it is not in the anchor text any more - but it used to be.

Interestingly - the same page is not supplemental for a more recent, relevent keyword search.