Pioneer Ao6 Not reading dvd anymore

[mekenphoto]

I have been using an AO6 since Oct.03 and it's worked fine. in all areas. Mac OS 9.2.2 Toast Titanium 5.2.1. Recently it won't read any dvd's that I burn. Will read cd burns fine. Called pioneer they said to flash firmware. Pulled out of Mac put in PC and updated the firmware on the dvr ao6, and I still get the this disk is not readable by this computer. eject or intialize. Has anyone had this problem too? and if so how did it get fixed? The dvd's spin up no problem on another Mac or PC. So I figure ask here to see if anyone knows the answer. Thanks