VFB is hidden if you change render size after having rendered

[Richard7666]

On Maya 2012 anyway. Say I render at 2048x1200, then do another render at 800x600, the VFB will vanish and I am unable to get it back without restarting Maya. Is there anything I can do to get around this?
The "Show VFB" button in the settings does nothing once this has occurred, all I can do is restart Maya.

[Fredrik Averpil]

setAttr "vraySettings.vfbSettingsArr" -type Int32Array 0;

Does the MEL above help?