I also won the battle, saw the battle report, got the popup about the armor and then the game crashed. The save is from the turn before the battle. I teleported my sovereign home and the game started to feel sluggish so I rebooted my computer.
http://dl.dropbox.com/u/8154115/DxDiag-2010-07-17.txt
http://dl.dropbox.com/u/8154115/Armorcrash/debug.err
http://dl.dropbox.com/u/8154115/Armorcrash/Elemental0_92-2010-07-21T14-52-38-890.zip
http://dl.dropbox.com/u/8154115/Armorcrash/Sluggish.EleSav
[Edit]
I fought the spiders for the armor again, only this time I clicked the autoresolve button as soon as tactical appeared. I won, got the armor and no crash.
[/Edit]
[Edit2]
I alt-tab'd out make the first edit right after the battle. When I alt-tab'd back to the game I got a DX Error - Onvalid call popup and the game crashed. No dump.
[/Edit2]