It looks like the code formatting from question Object.GetHashCode is bleeding over into tags and the user profile information. I haven't seen this on any other questions but it appears to be happening in FF 4b11 & IE 8.
This is possible due to old bugs in the Markdown renderer. We store the rendered HTML at the time of save, so if it was saved a long time ago.. etc.
I just edited, entered a space, and clicked save.