ggirzon,
I would recommend two things:
1) First if you haven't had the chance to yet, please run through the LoCE Windows CE BSP QuickStart Guide, it is linked below, and verify that this issue still occurs with a simple image built for ActiveSync:
http://www.logicpd.com/do...3/70000142_Rev_F.pdf
2) My other recommendation is to make sure that you are current on all of your driver updates from Dell. This sounds like it's a hardware interaction issue on the PC side and might have something to do with your USB Hosting driver on your PC.
Regards,