Device Manager continually expands and contracts

I've got a problem on my month old custom build where the device manager screen continually fully expands then contracts to just the computer name. It may happen 2 or 3 times in succession then again in 15 or 20 seconds; no kind of pattern, but it won't stop. The only thing I can find out through my research is that it may (probably) be a driver trying to install itself. There are no errors...