I'm not sure what's your problem , but it seems that is the poor quality of the image sensor of your cameras ( CMOS/CCD ).
If the problem is the image sensor there's no way to fix that , even be carefull because you can "burn" the image sensor.
-- AngelCarpintero - 21 Sep 2005
Answer
I agree with Angel. This sounds like a camera problem which Motion cannot possibly fix.
-- KennethLavrsen - 22 Sep 2005