Re: Update to 190.42 breaks Xinerama AND TwinView!
Thank you for the comparison log file, desperadus. It appears that 185.18.14 was also unable to detect your monitor, but the signal you forced it to drive using ConnectedMonitor just happened to work for it. I'm not sure what would have changed with 190.42 that would have modified that behavior. The only thing I can think of is that the order of display devices changed and DFP-1 got assigned to a different display device, but that's pretty unlikely. I'll try to track down your GPU and force it to not detect my monitor and see if I can find out what changed between those two drivers.
Given that neither driver is able to read the required EDID information from your monitor, it seems likely that there is a hardware problem in the monitor or the cable connecting it to the GPU. If you have a different DVI cable, it might be worth giving that a try. it would also be interesting to see what the driver says it finds if you comment out the "ConnectedMonitor" line and start X with "startx -- -logverbose 6" from a console.