I experienced something similar. When I tried to rebind the key for toggling the health bar to the key in the lowest row of letters on the far left, left to the 'y' key on german keyboards, left to 'z' on an english keyboard, the game crashed without an error message. I may have pressed a couple of keys in between the one I mentioned an the game actually crashing.
The computer has an Intel Dual Core 64 bit processor, the os is Windows Vista 64 Home Premium German with Service Pack 1. My graphics card is an ATI 4870 model. The Demigod version I use is from Impulse, with english voices and text.
Here are the last few lines of DemigodLog.txt:
info: Setting audio parameter 'TEAM' to value '1.000000'
debug: Loading module '\000/lua/ui/game/keybindings.lua\000'
debug: Loading module '\000/lua/keymap/keydescriptions.lua\000'
debug: Loading module '\000/lua/keymap/properkeynames.lua\000'
debug: Loading module '\000/lua/ui/dialogs/exitdialog.lua\000'
debug: Loading module '\000/lua/ui/dialogs/dialog_options.lua\000'
debug: Loading module '\000/lua/ui/menus/menubuttonframe.lua\000'
debug: Loading module '\000/lua/options/module_options.lua\000'
debug: Loading module '\000/lua/options/module_keybinds.lua\000'
debug: Loading module '\000/lua/keymap/userbindablecommands.lua\000'