crobb305 - 4:16 am on Mar 14, 2011 (gmt 0)
It looks like everyone of the malformed urls reported in GWT has this appended in front of the file name: %E2%80%8B
Everyone of these junk portals are appending that, and Googlebot is encountering 404 (30 to 50 on each crawl). My best bet might be to create an htaccess rule to strip that out, and 301 to the correct form, but my htaccess skill is poor. I'm not sure how to strip it out. Like you said, it would be better to keep those visitors coming from those sources, by doing a redirect.