This happens to my system regardless of KMS, If I use kernel append: nomodeset the same thing happens (unstable VGA output on laptops external port).
With regards to obtaining an image (a wobbly one) at all on external VGA: it seems only possible at 75Hz, if I attempt to change this to 60Hz in Preferences -> Monitors this is where the whole system hangs.
Just to add some extra information:
This happens to my system regardless of KMS, If I use kernel append: nomodeset the same thing happens (unstable VGA output on laptops external port).
With regards to obtaining an image (a wobbly one) at all on external VGA: it seems only possible at 75Hz, if I attempt to change this to 60Hz in Preferences -> Monitors this is where the whole system hangs.