Mouse functions not working

The only function which works w/my new imac, August 2011/21.5 base model, is the up, & down scroll function.
Under system preferences all functions are clicked off.

Apple care has no suggestions.
Had a previous problem, apple store replaced the mouse when
simple movement of mouse caused the zoom function to increase approx. 1000 %.

(Actually mission control, & secondary click do function).

They suggested bringing it up for a genius session. I'm trying this first as i don't want to leave it for any length of time.

Thanks,

 

most probably software issue as it has been a problem w/mouse since purchase.