Due to subtle differences between the screen colours between nt & 2000 you'll probably have to make 2 versions of the check, one for each OS, then use SystemInfo( "os" ) command to determine the current OS and run the relevant check.
I found this same problem with image mapping.
The reason is because of the system colors default is different between the platforms. So, In Display properties of all our test machines we set the "3D Objects" to 192, 192, 192 and the "Active Title Bar" to 0, 0, 128. You can set them to any color as long as you learn the image check after you decide a standard. This fixed our problem with image maps. I think it may help you with image checks. Try changing your Win2k colors to match your NT colors.
"If your not part of the solution, there's good money to be made in prolonging the problem."
If your not part of the solution, there's good money to be made in prolonging the problem.
Ok from my experience you dont need to worry about screen resolution or amount of bits (at least between 16 and 32) but windows 2000 uses Windows Standard appearance (right click, properties on desktop). However this standard is different to NT4.0, windows 2000 has the standard NT4 appearance called windows classic. All our bitmap checks worked after changing that