I have the CD/DVD/SAT/NAV w RSE and the player won't play any discs. When inserted, the disc feeds in and out three times and holds it the third time with a message, "can't read disc". I sent it to a company in California to change the Optic. It worked for about 6 months and now is doing the same thing. The vehicle is 07 Suburban LTZ. Did I just happen to get a faulty optic installed or is something damaging it or is it another problem completely? I've tried the ridiculous cd cleaner disc and tried blowing some air from a keyboard cleaner to no avail. What's up with this thing?