Poking around at MSDN I did find a help on error codes that says that Code 39 may mean that the driver for a hardware device can't be loaded, and gives several possible causes that might not be corrected just by uninstalling/reinstalling the driver. There also seems to be an ambiguity about whether, for USB ports, they mean the driver for the port or the driver for what's plugged into the port.

The article I found that looked most applicable is an old WinXP advice, and has a "Wizard" that's recommended as part of the fix. The Wizard probably won't run on Win7, but the rest of it looks like it should be OK for Win7 since the places it says to click are all there in the Win7 Device Manager.

Since the problem here has been solved, it's redundant information, but I'll put the link here anyway just for reference and because sometimes it's easier for me to find stuff here than elsewhere when someone comes along with a similar question:

Explanation of error codes generated by Device Manager in Windows XP Professional
Article ID: 310123

"Code 39
"Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)"

This Code 39 appears to be a common problem that is most frequently encountered by users for optical drives (CD/DVD) but could pop up for any piece of hardware.

It should be noted that there are several "classes" of codes, many of which include a "code 39" that means something entirely different than this one associated with hardware management. A reasonably deep search is about like looking for what a word means when you don't know what language it came from. You can get lots of answers from places where the question doesn't mean what you think you're asking.

John