I am using the X-Micro DG3X USB Dongle Class 2 with my Dell Axim X50 PDA and Logitech Mobile Freedom headset. I have only been successful getting the BT to work at my office location using the 1.3.2.7 driver from X-Micro's website. The office system uses an Intel USB Chipset for both 1.1 and 2.0.
I have tried the same driver at home on two different systems, one using an Intel 1.1 USB chipset, and one using the *shudder* ALi USB 2.0 chipset. The device installs fine using the driver, and I see no conflicts, but it has the tendency to drop the driver from the device manager when scanning for devices. I have tried numerous drivers from 1.3 -> 5.0 for Widcomm BT adapters and the 1.3.2.7 version is the only one that seems to work minus this issue. Update: 5.0.8.1 appears to work as well without the WHQL errors.
I have troubleshot USB power problems, but I have yet to troubleshoot Wi-Fi interference.
Apologize my ignorance, but I am new to BT and it is a bug that has *bitten* me.

Has anyone else had problems with their adapters dropping from the device manager?