I've had similar problems the last couple of days. It has happened with 2 different skins, shock v4 and hemi day. I do have DFX installed but do not use it much so I don't know if that is what is causing the problem.
It's very random and happens on different screens. RR will crash, not freeze, and the microsoft send error screen pops up. This happens with out me even touching the screen. Winamp will continue to play music, the icons and taskbar remain hidden. I can click the start button area and restart RR and it will restart while winamp continues to play and pick up where ever winamp is.
I have not checked the error log yet to see what is causing it.