Funnily enough I have the same setup as I used to use the Haicom with my old XDAIIs.
Basically Pocket PC's with mini USB connectors will not work with cabled GPS receivers at all.
I've just gone for the following Bluetooth GPS receiver
http://www.mobilefun.co.uk/product/8590.htm
Fair enough it probably won't get as good a signal as the latest SirfIII bluetooth GPS receivers such as Rikaline 6033/Holux 236 but it is half the price and should give roughly the same sort of reception as your old Haicom reciever (great pieces of kit BTW!)