Keyboard option keys work as command keys
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.)