My friend was unable to report this issue himself, his account isn't logging in to the forums at the moment.

Windows 7 64-bit
Text DPI set to 150 or greater
Diablo III 1.0.1
Fullscreen

This causes his mouse cursor to not track properly. Lowering the DPI is a workaround, but due to vision issues this is not an easy workaround for him. He can play it in Windowed mode, but this is not optimal. I find it curious that text DPI is causing a conflict with mouse cursor tracking. Please advise.