Problem with Nav

I have a CPO '08 BMW X5 and have a strange problem with my Navigation and reading the DVD. My Nav goes out intermittently while I am driving. It can't read the DVD disc. If I eject and reinsert, sometimes the Nav can read the disc and sometimes it can't. I do it repeatedly until it does. Sometimes it takes 1-2 tries...sometimes 6-7 tries, but it does ultimately come back. Also, if the Nav stops reading, sometimes if I turn off and on the car, the Nav starts reading again.

I talked to my local private BMW service guy and he said my DVD player is just dirty since it reads intermittently. If there was something wrong, it wouldn't read at all. He told me to grab one of those DVD cleaners. So I went to Amazon and bought Digital Innovations CleanDr Laser Lens Cleaner. I cleaned my DVD player (multiple times), but the Nav continues to have the same problem.

Unfortunately the Nav is not covered in BMW CPO. Just wondering if anyone had any insight what's going one? Could it be a loose wire or fuse? Thoughts?

Thanks!!!