third monitor: cannot display this video mode optimum resolution 1680x1050

[Ronald Pottol]

This is on an iMac 20-inch, Mid 2007 running Lion, monitor is a Dell that does 1920x1080 (and I have one plugged into the external display port on the Mac as well).

Suggestions? It looks like the same issue people reported on the beta forum.

Thanks,
Ron

[ChristianP]

The log shows an error in reading the EDID of your display and because of this only some standard resolutions are listed. We don't know exactly what is causing the reading error. Are you using an HDMI connection? Thanks