aTV not recognizing thumb drive

I just updated my aTV to 2.4 firmware and have attempted to install the 3.6.1 software from the thumbdrive using the usual procedure. I’m been doing this for over a year so I am no n00b. It doesn’t seem to even see the thumbdrive now and will only boot from the internal harddrive. I’ve tried it now with two separate Memorex thumbs, my original 256mb and a newer 512mb version. I’m not sure what to do next short of doing a complete factory reset.

The USB port worked fine as of yesterday with the 3.5.6 aTV software under the 2.3 firmware, as I had a external hard drive serving media.

Any ideas as what might have happened?

Issued solved. Zeroed out the thuumbdrive and reinstalled. But I think the problem was in the USB hardware, somewhere. A loose connector or else I just wasn’t shoving it into the port all the way.