Well i have the logitech g700s and on my 2 back mouse buttons lower and upper. i used to have the bottom set to switch weapon and the top set to switch weapon and crouch. it helped me play better and get better strafes and what not but now i cant seem to be able to get it to do it anymore

So i havent played cod4 in a while but i started playing again and when i used to play i had 2 of my mouse buttons set to switch weapons and then one of them set to crouch which was most comfortable for my play style but i cant get the mouse button to hold 2 keys anymore and help?