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.)