Yes, I am. Seriously, I've tried four of the usb to serial adapters. Some work some of the time for some devices. None work all the time for all devices. I did not buy cheap adapters either. The one that works the best so far is a Keyspan.

So I looked a bit closer at my laptop, and sure enough, there is a slot in it with a nifty little door that I completely overlooked. I ordered the card you linked to above along with a couple more RS232 cables.