Lately, when I've plugged in a hi-speed USB device into a high-speed port, the device will function, then it will disconnect (I hear the Windows sound, and the port connection light on my hub goes out) then it will re-connect (with associated sound and port connection light), then disconnect and so on in a vicious cycle.
When the problem first appeared a couple of months ago, I was plugging in the devices directly to the motherboard. To troubleshoot, I tried out a powered HP Hi-speed USB hub, and plugged in the devices without any problems. Thinking that I had a power problem all along, I purchased a Belkin Hi-Speed powered hub and haven't had any problems until recently. Only the Belkin hub is connected to the high-speed ports (I have 4 on the back of the computer). All of my other non hi-speed USB devices are plugged in USB 1.1 ports.
I have also tried removing the "NEC Enhanced USB" driver and let Windows reinstall it, but I haven't had any luck getting my devices to stay connected.
My three hi-speed USB devices are a MicroAdvantage 128MB thumb drive, a 80GB Western Digital External hard drive, and a Creative Zen Micro.
Does anyone recognize the symptoms of this problem? I've searched the forums, but I haven't found anything quite like this.
I would like to mention that after alternating in connect/disconnect cycle for a while, eventually the port seems to revert to a normal USB 1.1 port, and I get the Windows warning that a high-speed device is connected to a non-hi speed port and that I have hi-speed ports available (even though the device is directly connected to the hi-speed hub that is connected to a hi-speed port).
Any help would definitely be appreciated.