MacBook has problems with external monitor but iMac doesn't I have a small Sony TV which is colour balanced for video editing. Note: it does not have DVI or HDMI ports.

When I plug it into an iMac using VGA and the Mini Display Port adapter, it is fine (using the native resolution).

However, when I plug it into my MacBook using the same setup, it is unable to determine the correct resolution for it. (It thinks it is 4:3 and uses 1024x768, but in fact it is 16:9.)

Anyone know how I might fix this problem? There are no alternatives in the display settings.
Not all monitors are the same - I bought a monitor from a friend to use for extra screen space space with my 13"MBP (Mid 2009). It was a nice VGA widescreen LCD monitor but no matter what I tried my MacBook Pro could not send any kind of signal to it. All connectors were verified to work perfectly well and the monitor also worked perfectly well when attached to a nearby PC...