zumo 500 & SD map storage/reading help needed

Firstly it's not my unit, so i'm reporting this "blindly" on behalf of a friend...

Zumo 500 with 2gb SD card. with europe mapping on the card.

Problem is that when he uses the unit to get back to spain, the unit doesn't read the card & crashes, he's found a "round the houses" way to find major cities, but this isn't easy to use as it should be..the pre-stored UK mapping works fine though

I plan to get the latest updates when he visits next, but i thought it best to ask the font of knowledge here as to what these are & any other recommendations/advice?

thanks.

I use these things but don't particularly understand them, I love the simplicity
of my Garmin i3, & the features of my mio c710, but will change these for a zumo 550 when garmin iron out the bugs/cradle issues...

Two things, either the mapping info hasn't transferred correctly or you're running the new SDHC enabled firmware that introduced bugs with non SDHC cards.

If he is running on old firmware, all sorts of things can happen.

One possibility: Double maps. If the maps loaded on the SD card are partialy the same as the pre loaded map (part) of the 500, this might be the cause of crashing as well.

The Zumo wants to find a certain map segment, but finds two of them. That it can not understand, so it stops completely