Environment
OS: Win 7 x64
M/b: P7P55D-E PRO
Case: Antec MT Proto
The issue is with the front-panel ports. Albeit connected to the motherboard, there is no visible event when my thumb-drive is connected. The same device works great on the back-panel ports.
Hardware re-scan did not notice any changes.
So ... the question - how to find out whether the problem is with the USB port, or with the motherboard?
EDIT: After reading the notes I started to remove the existing connector cable a prior to putting a new cable in ... and realized I'd connected the cable to the IEEE1394 pins
What a stupid thing to do! )+:
Thank you all

