USB 2.0 Flash Drive oddity

[Firejack]

I bought a couple of 512Mb USB 2.0 Flash Drives from Aria a few weeks apart last month.
The first one, PQI Traveling disk, works fine on my laptop (Toshiba Sat Pro 2100) and its USB 1.1 ports. However on my Desktop (A7N8X Deluxe mobo) it only works when I plug it into the rear USB connections. I presume the ones on the front of my case that I plugged into the motherboard are USB 1.1 only and the rear USB 2.0.
Now this is the totally bizarre thing. The second USB 2.0 Flash Drive I got, an Unbranded Flash Drive, doesn't work on my laptop. Yet it works fine on any USB port front or back on my desktop.
Both system are using Windows XP Pro with all the latest patches and drivers.

Anyone have a clue whats going on here? I don't.

[Shogun]

What do you mean by doesnt work? Isn't recognised or what?

[Firejack]

Yes. I get a "USB Device Not Recognized" Error message.