Navigation System Cutting Out

[admranger]

This has started happening since the temps have been up (both in Vegas and here in DC area). Upon starting the X5, the nav will not start up from time to time. It appears to be heat related, but it is pretty random. Sometimes it says it can't read the disc (even though it was working minutes ago or the day before). Sometimes it gives a message that it is unavailable or something like that. It is becoming more frequent (it seems), but maybe it is because I'm using it more frequently than ever before.

Has anyone experienced this?

I'm becoming very dependent on the nav system being in a new area. It is a very, very nice feature when you have no clue where you are!

Thanks for your help.