Explorer.Exe Hangs On Every RDP Or ALT TAB

A few months ago my Windows 7 installation seemed to hit a hiccup -- explorer.exe started hanging whenever I attempted to return to the desktop. That's the best way I can describe it. Explorer is just fine and happy if I stay within Windows, but if I either

a) Connect to the machine remotely via RDP (i.e, I am connecting to this machine from an outside computer), when I get to explorer..
b) Run any sort of full screen application, for this example let's say Valve's Half Life engine, although everything else does it too, and then Alt-Tab back to Explorer..

Then when I return to Explorer it is hanging -- the mouse shows the busy wheel on the task bar, and it never returns. I can click, I'll be told I can check for solutions and close the program, and voila -- explorer is killed and restarted, all is well.

I have: Replaced the display drivers, no effect Insured the installation is up to date, no effect Sweared at it, no effect Installed windbg, saved a dump file, realized I'm not a developer, cried into a pillow, no effect

I don't think this information has any use, at least, there's nothing on search engines, but here goes:

- <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> - <System>
<Provider Name="Application Hang" />
<EventID Qualifiers="0">1002</EventID>

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