Hi d13f00l, sorry for the late reply. Since the individual displays in TwinView can run at different refresh rates, the driver assigns a unique number as the "refresh rate" as reported to the server so that the modes are distinguishable. Otherwise, you wouldn't be able to switch between modes like "1280x1024,NULL" and "NULL,1280x1024" with xrandr.
As for the refresh rates, your modes have these rates:
- 1280x1024 --> 60.02 Hz
- 1024x768 --> 60.00 Hz
- 800x600 --> 60.32 Hz
- 640x480 --> 59.95 Hz
When you plug in your TV and use your DFP,TV metamode, you're using your 640x480 mode for both displays.
There is no way to synchronize to two displays at the same time because they could be running at different rates or out of phase. It's surprising that you didn't see tearing with older drivers.
zsnes has some modes that use OpenGL and some that don't. Are you sure you're using one of the OpenGL modes?