Windows – “Show window contents while dragging” keeps getting disabled

On my Windows 7 Enterprise x64 machine at work, "Show window contents while dragging" regularly gets disabled.

I currently have Visual Effects set to "Adjust for best appearance", still, every now and then, I only drag window borders around – not content.

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When I experience this, the "Show window contents while dragging" checkbox is still checked. Unchecking the box, applying settings, checking the box and applying settings restores the functionality.

I previously used "Custom" as opposed to "Adjust for best appearance". When I experienced the issue back then, "Show window contents while dragging" would be unchecked. I could check it, apply settings and "a while" later, the issue would return.

I am not aware of anything settings in logon scripts or GPO's that would cause this. Also logging off and back on, or even rebooting the computer, doesn't reproduce the problem (at least not consistently).

I rarely log out or reboot, but I often connect via RDP from home. I've tried connecting to my session from a Windows XP machine, both with "Show window contents while dragging" disabled and enabled in the RDP client. In either case, "Show window contents while dragging" was enabled and working when logging in locally – as expected.

For what it's worth, my computer is fitted with an nVidia NVS 4200M and Intel HD 3000 graphics cards.

Have anyone encountered this or similar problem? Any ideas what could be causing this or how to determine?

Thanks!