tedster - 8:48 pm on Oct 13, 2010 (gmt 0)
It appears to be a away of time stamping the css file. The query string would be a way of telling the browser "if you request this file again and that query string version is not available, you'll need to take a new version".
I've never seen this done, and I'm not clear why someone would do it. CSS files usually don't change very frequently, and when they do change, then normal server requests should handle it effectively.
So I am also abut curious - even a bit mystified. Anyone have any deeper insight than I do"