[1Z4][CRASH] "DX error: Invalid call" Win7 64bit

I started Elemental, successfully loaded a saved game, ALT-TABed out to windows explorer to clear out old debug/crash reports (to ensure I'd only find recent info in case of problems), LEFT CLICKED on the Elemental's entry in taskbar to get back to Elemental and got a black screen with the message "DX error: Invalid call", I hit "OK" and Elemental had closed.

http://dl.dropbox.com/u/5475789/debug.err

no crash report or usual windows crash message ("strategy game has closed etc.")

http://dl.dropbox.com/u/5475789/DxDiag32bit.txt

http://dl.dropbox.com/u/5475789/DxDiag64bit.txt

This is the first I've seen this.

Experimenting shows the cause to be related to:

1-clicking on the Elemental taskbar entry to get back into the game after ALT-TABing out of Elemental.  ALT-TABing to get back into Elemental doesn't cause this crash and I get back into game ok.

**2-the save.  Recent saves exhibit this, the original save made just after creating this game do not

http://dl.dropbox.com/u/5475789/LatestSaveThatDXCrashes.EleSav

http://dl.dropbox.com/u/5475789/GameStartSaveNoDXCrash.EleSav

**Correction -- point 2 is wrong -- it doesn't crash the first time I do this (I get back into the game ok) but if I do it a second time it'll crash.  The recent saves still crash every time I do this.