What kind of camcorder do you have? Most (if not all) miniDV camcorders have FW ports. So why not use FW?

I'm sure you have a good reason, I'm just curious.

Firewire and USB2 use a completely different protocol to communicate/transfer information, therefore, it stands to reason that a simple adapter has to do considerably more than merely connect the two ports... a bidirectional layer of interpretation and interchange would be required. It would also make sense that if emulation is correct, the data stream would conform to standards of FW and therefore indistinguishable by the application. There is a little matter of rates of transfer. Given that at the practical level, USB2 is already slower than FW, through conversion, transfer rates would drop down a little more and it the application actually tests the actual transfer rates (much higher needs for HD version), it is entirely possible that the converted stream may fail such a test. Given the slower rates of USB2, I'm not sure that it would make sense for someone to produce such a device.

But to be specific, I have not come across such a device yet.

I SERIOUSLY doubt that would work. But if it does let me know.