Do you have a link to the GPS?
I found this links on the net:
http://www.icpdas.com/products/GSM_GPRS/wireless/UG-200-RS232.htm
and
http://www.freewtc.com/products/gps-mouse-receiver-rs232-or-usb-1570-61296.htm
and
http://www.freewtc.com/products/gps-mouse-receiver-rs232-or-usb-1570-61296.htm
mine is RS232 version, it use LS4000 gps detector. It work on my pda, maybe there is some problem with the protocol.. 