Maxamus, where did you get the Navi CD from? I have an MFD2 which I got from ebay and had a similar problem with CD's sourced from ebay, "CD-ERROR" & "NO-NAVI-CD". These issues are usually down to "Copied" CD's, they work for a while and then turn to Sh1te. I bought a genuine CD from
www.navshop.com, which is Teleatlas's shop, and I have never had any navi issues since. If your CD is a copy then I think thats the problem, Bob on vwnavi.com will probably say the same. So either try to get an original cd to verify, a kindl dealer may help, or buy an original. If your CD is original then return it.
There are what look like originals on ebay but some are poor copies, the cd is orange but should be blue and yellow.
Dave N