Flash drive not working in USB 2.0 ports

I have a USB 2.0 flash drive I’ve been using since last spring. Starting just the other day, I can’t get USB 2.0 ports to recognize the device on any computer. It just pops up a “Device Not Recognized” bubble from the taskbar. The device still works fine in USB 1.1 ports.

This is a problem I’ve had with every computer I’ve checked it on (about a dozen computers at school as well as the two I have at home) and it just started a few days ago.

The device is a 2.0 device; when I plug it into a 1.1 port, it gives me the notification that it would be faster to put it in a 2.0 port. There is also no dirt or signs of damage on the device or the contacts.