Overview:
My Host OS is Ubuntu 10.10 and guest OS is WinXP on the VirtualBox version downloaded from Oracle including "VirtualBox 4.0 Oracle VM VirtualBox Extension Pack" so that USB passthrough works. This works in general (I was able to back up my iPhone to iTunes in the guest OS), but some devices aren't available even though they're ptrovided in the VirtualBox settings.

Specifics:

• In the VirtualBox settings for the guest OS, there's the part where you can select which of your USB devices should be visible to the guest OS. I've selected several devices including the iPhone. So far so good.
• Then an iOS upgrade came along; my iPhone is now in DFU mode (or recovery mode?) and represents itself not as "iPhone" but as "iPhone (DFU mode)".
• I have now also added this device to the list of USB devices that the guest OS should see -- but it doesn't see this device.

Questions:

1. Am I right in expecting that the guest OS ought to see the DFU device when I add it in the VirtualBox settings?
2. What steps do I need to take so that the guest OS will really see the DFU device?