Thanks redge, I had viewer inputs disabled.
It appears to be checked by default with SBS 2008.
I don't think I've seen that setting used before which is why I didn't notice it.
That's my excuse anyway
I've installed 1.0.8.2 on SBS 2008 64 bit, and when I connect to it from an XP PC I can only connect in view-only mode. I've set different passwords for normal and view-only. It happens with or without the video driver installed. I've tried it with VNC authentication, and MSLogon 1 and 2 ...