Memory allocation error?

Hi all,

I've got a medion pda, which has navtec gps software on it, which was bought about 6 months ago. Its now coming up with an error almost everytime I use it "memory allocation error".

What does it mean and how can I fix it, or do I need to take it back to where we bought it?

Its so frustration esp. as I'm coming to an important part of the journey and then the error comes up and crashes the programme - obv. its quite dangerous to try and set up my route journey again as I'm driving and the buttons are so small!

Hope you can help - thanks!