i have been having problems with mine also. Recently brought it and it wasnt working right.... sometimes it turned on and worked fine then without warning it would freeze and not do anything until i turned the car off. The screen pop up button didnt work etc etc. So last night i took the whole lot apart and spent 3hours going over the navi unit motherboard... resoldering and replacing parts then did the same on the tape deck, put it back together and hey presto so far touch wood it woring fine again. Scrren pops up when i want it to, the cd player works when i want it to. So next thing is to get a pc wired to it (fairly sure i can do it) then ill have guages displayed on it also