tedster - 10:17 pm on Jun 22, 2010 (gmt 0)
No, the filter doesn't tend to de-index the filtered page - it's just a filter, and it just hides other URLs from view in the search results. So it sounds like something has gone a lot further south in this case.
Now I would say it might be worth a reconsideration request. But first, have you eliminated all the manufacturer's boilerplate from your site's pages? If so, then you've got something to write about.