Movie resolution in windows 7 is different from windows xp. What went wrong?

I have recently migrated my system from windows xp (64bit) to windows 7 (64bit)operating system.

I am using MATLAB R2007b 32 bit version.

My image processing code creates a movie containing nearly 100 frames. I create my movie as per the following code: combmov=avifile(movname,'compression','Cinepak','fps',10,'quality',80);

When I ran the code in windows xp, quality of the movie generated (pixel resolution) was very good. But, in windows 7, running the same code, I get a movie with very bad pixel resolution.

Please suggest me the solution to this problem.

Thanks in advance