I found some informations about your problem:
You should run a SW which is working on your Zaurus i.e. qpeGPS . This is freeware which is the whole idea behind Linux. I think you can only sell the card Holux GM270 but not the SW.
The SW can be downloded .
I found some further informations about your card (Holux GM270) it seems that it is not running out of the box, but if you follow the link you find a nice howto.
Just my 2 cents