I've been using Banshee for a while, this just started happening the past few weeks.
When I exit Banshee, my CPU usages goes to 100% and stays there. It continues until I manually kill the Banshee process. I don't get any error messages when I run it in a terminal.
Any ideas? I used to use Rhythmnbox, but it stopped syncing properly with my old, old iPod. Banshee works with the iPod, but I have to kill it every time I close it.