DE2-115 D5M image issues

Howdy,

I am an absolute FPGA beginner... but for a beginner I have a very nice collection of Altera products:)

I am running Quartus Web Edition v14 with DE2-115.

The updated example from the CD that comes with the D5M compiles and runs fine.

The default resolution provides a nice clean VGA image, with minor color balance problems.

However, when I change the resolution to 640x480 by uncommenting the setting in VGA_Param.h,

the resulting image has vertical bars of noise.

Another thread with a different but somewhat similar issue resolved that issue by making clock changes to the .sdc file.

I have played with various changes to D5M_PIXCLK in the .sdc file... from 20 to 48, with no visible changes in the output.

Thanks,

Rich