Keyboard option keys work as command keys

I have a interesting Option Key problem but I couldn't find any solution.

I am using iMac 21,5" and running Mac OS X 10.6.8 Snow Leopard.

My keyboard is apple wired aluminum extended keyboard and my layout is "Turkish QWERTY PC". My problem is both Options key work as Command key and , I cant type special characters.

I opened Key Viewer and when i press option key it shows as Command Key.

Note : I have a logitech g500 mouse

Note2 : I tried 3 diffrent keyboard ( Microsoft, logitech and apple ) result is same.

Note3 : system prefs/keyboard/keyboard/modifier buttons are default , and when i changed control button to option button and press the control button its type command button again.

Is there any solution to fix this?

Thanks a lot.

Do you have the Logitech Control Center (LCC) software installed?

if so uninstall it and see what happens.

(I had a few issues when I had it installed with crashing and strange things happening to my keyboard (I only had a Logitech Mouse) which at the time all the knowledge on the interwebs told me was down to LCC being a pile of horse puckey.)

Try running the Keyboard Setup Assistant again

Open a terminal window and enter the following:

sudo open /System/Library/CoreServices/KeyboardSetupAssistant.app/Contents/MacOS/KeyboardSetupAssistant