If your machines aren’t automatically having their display resolution set to their monitor’s native resolution after deployment via MDT, this may be the cause of the problem.
Although I’d previously deployed Vista and Windows 7 using MDT 2010, I’d never seen this problem. The issue occurred with a captured HP ProBook x86 Windows 7 Professional build.
I had to edit the unattend.xml for the task sequence in question, and delete the Display section from oobeSystem –> x86_Microsoft-Windows-Shell-Setup_neutral. Once this was done, the strange default of 1024 x 768 (where did that come from?) was no longer applied, and Windows Setup detected and set the maximum resolution.