Not sure if anyone cares about this anymore, but I just bought a Sony MicroVault thumb drive, which is apparently USB 2.0 only. I plugged it into my Antec Sonata case's front ports, and it didn't even notice the drive was there. Worked fine on any of the rear ports though.
I read this and other posts about the problem and called Antec at 1-888-542-6832 for the replacement part for the front panel ports. The person on the other end knew about it, and was quite pleasant. She apologized for the inconvenience, and said I must have gotten "old stock." I'm assuming the new Sonata's have the "fixed" part. I got mine last June. I got the new part in about 3 days by USPS.
I thought the same thing as syberscott about USB 1.1 and 2.0 pin outs being the same, so I wasn't sure exactly what they could have gotten wrong with such a simple part. All I can say is that I put the new part in and USB 2.0 devices now work like they should when plugged into the front panel. (I.E., The thumb drive is recognised as a USB hard disk.) The part replaces all of the ports under the little silver door (since they are all on one small PCB). On my case, they used some plastic caulking/glue to hold the connectors onto the PCB. This was easy to peel off though, so getting the connectors off was easy. Two plastic tabs/clips hold the PCB in place and removing and installing was straightforward. As an FYI, the part I removed also had USB 2.0 silk-screened on it as did the new one I put in. The new one had the USB 2.0 in a different place and the traces were definitely different.
-cap