I appear to be having an identical issue to someone else who posted the following in the "race to dump the 4870 rom" thread, which I will quote below: I have the official Radeon 4870 from Apple with no modifications made to it or to my system. v0n says the issue occurs with two separate flashed 4870s, so I'm unsure if it is a hardware issue. The only difference between my crash log and v0n's is that mine says: Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at /random address/ Does anyone have any idea what could be causing this issue? Any thoughts on troubleshooting it? The only other issue I have that I have noticed is that I get this weird horizontal black line that appears approximately 1" below some application windows. Other than that, everything seems just fine. There are no anomalies in Windows and gaming performance seems fine, so I'm not sure it's a hardware issue (any way I would be able to test for sure?). Thanks for any and all help!