Not all lexar cards are the same, some (all?) are in fact made by sandisk.
If you have problems with the card then return it from where you bought it, or return it to lexar as they should have a 5 year guarantee.
If you have access to a pc card reader or a digital camera, try formatting it in there first. I don\'t know why this works but it usually does allow the zaurus to format the card afterwards.