Has anyone had mysterious overheating issues with the AT90USB? I haven't done a large number of projects with it, but I have one causing me some problems. The IC gets quite warm when connected to a windows PC - ultimately, it will stop recognizing a USB connection has occured until it's allowed to cool down a bit.
The IC is @ 5V 8mhz, and there isn't anything special about how the USB interface is hooked up. The power is external (not bus powered).
I'm going to try it at 3.3V to see if that provides a better result, but has anyone stumbled across this problem before?