I am running Ubuntu 11.10 64bit with a Sony VAIO VPC F11. It has an NVIDIA GeForce 310M video card, with the latest Nvidia drivers for the 64 bit linux, and a Windows partition with Win7 64bit.
NVIDIA driver version is NVIDIA-Linux-x86_64-280.13
External monitor is Samsung SyncMaster P2770
If I boot into the Windows partition, the HDMI works as expected, with sound and video-- under linux, the HDMI port is not recognized at all, apparently, and provides no signal to the attached monitor. The nividia-settings tool does not recognize any monitor connected to the HDMI port.
Disper is installed and cannot recognize an attached external monitor.
Can anyone help me diagnose this issue and fix it if possible? The laptop has only the one HDMI port to connect any external monitor, so it I can't get this working I'm stuck using either the laptop screen or Windows.