google indexing fake blog paths
 

I was looking at my google webmaster tools account and it lists several pages as crawl error 500. The bizzare thing is that the pages don't technically exist. I don't have these folders and I can't imagine I have these paths linked to anywhere on my site. Google seems to be indexing fake blog paths. It must be a bug somewhere. Here are some examples. The links usually work, but they don't make sense. They aren't the right paths.

Code:
http://www.physicsforums.com/blog.ph...ecent&page=200
http://www.physicsforums.com/blog.ph...ecent&page=195
http://www.physicsforums.com/blog.ph...ist&m=5&y=2007

They also seem to have a combination folders of "archive', "wedding", "chat" or "clientscript".