No, it's an HP. But you may be right, it may be a mechanical problem. I don't think so, though, because I have two monitors and I've tried plugging into both of them, and all the 4 ports available. It's programmatic I think. Something is happening when the computer locks. Or maybe it's the screensaver, I don't know. But I've turned off all those power management features. I did it for the usb ports and I also did it for the screensaver/power management settings. So I don't know of any other things to try.
The weird thing is that the computer still knows that something is in the port, it just stops reading it after it disconnects. If I just pull it out and replug it in, it's fine (minus all the errors on the screen from all the live programs getting interrupted).