Re: Forcing 60hz with twinview.
It might be useful to debug whatever is going wrong when you aren't using the ConnectedMonitor option. Its possible that ConnectedMonitor is causing the 60Hz issue, as that option should not be neccesary unless the driver is failing to detect the type of display attached to your videocard.
The EDID in your bug report shows that all the native modes run at 60Hz.
If you connect only your "Sceptre X9G-NAGA IV" DFP in a single headed configuration, without any other X options, and use the "1280x1024_v" mode to drive it, what do you get?
Also, are you setting sync-to-vlank anywhere?