All my posts for the past month have hit a bug in Community Server that strips out the leading "http://blogs.msdn.com" when I link to other Microsoft blogs. If you read this blog via a syndicated feed (e.g. Bloglines) then those links were broken for you — my apologies.
I suspect the bug is in the Community Server URL-rewriting routine, since it began when I started adding title tags to my links. As a workaround, I've stopped adding title tags when linking to other Microsoft blogs. I've also manually fixed up the links in the old posts.
Update: Scott Watermasysk says this is actually a long-standing problem with IE's WYSIWYG editor. He had a server-side fix for it in .Text, but Community Server hasn't been patched yet.