Screen freeze with 'Invalid Parameter for Capture' message

Hi,

I am running a gamebot using sikuli. Every now and then, the screen freezes, the mouse pointer turns into the precision selection pointer ('+' shaped) and i get an overlay message 'Invalid parameter for capture'. The look and feel of the screen at the time is the same as when sikuli's selectRegion() is run. Even the 'Invalid parameter for capture' message overlaid across the screen is the same font as the 'Select a region on screen' message that is displayed when we use selectRegion(). This frozen screen and the message usually goes away when is click anywhere on the screen.

However, there is no usage of selectRegion() anywhere in my script. All regions are pre-defined by their pixel coordinates.

Has this behavior of sikuli been encountered before by anyone? Any ideas how to deal with this?

Thanks