The most recent version, it wasn't a clean install but things worked fine, I worked through the issues with a nonclean install and I do use automatic update.
The only issue I've noticed since the most recent update which is 7.0.1426 it starts a bit slower now, well it starts at startup but it doesn't show up in the system tray for a few seconds, my pidgin is able to start before it, but I don't think that's an issue.