Falkie

Hi all. I'm new to this forum and am hoping that someone may be able to give me some help/advice. I have a 2009 XKR. The satnav stopped working properly a few months ago - kept saying it couldn't read the disc. Took out the DVD and yes, it looked quite scratched, so I got another updated disc for around £25 and changed discs. All was well for a week or so, but now the satnav works randomly, sometimes does multiple crashes and resets as driving along, sometimes shows the map, sometimes doesn't and sometimes has a voice and then no voice - usually of course when you are in a town and need directions ! I am guessing that it may be the DVD reader that needs replacing (it frequently comes up with checking disc) , but looking at the price of them, that doesn't seem a sensible option - especially when it is a guess. All the other touch screen functions seem to work OK. Has anyone else had a similar problem with their satnav and found any solutions ? Just also would add that the company I bought the updated disc from is one I have used before on another vehile with no problems. Many thanks in advance :)