Can't shoot when scoped in

[gtrx]

Shoot key: left mouse
Scope key: alt
I can't shoot with my sniper when I'm scoped in. But setting my shoot key to X, it works. Scoping with /altaction and shooting works. I even reset my binds and set them to the following, but still not working:
Forwards:                W
Left:                    A
Backwards:               S
Right:                   D
Attack:             MOUSE1
Special:              LALT
Jump:               MOUSE2
Crouch:             LSHIFT
Reload:                  R
Weapon menu:             B
Next weapon:          DOWN
Prev weapon:            UP
Show scores:             ?
Chat:                    T
Team chat:               Y
Commandline:             L
Console out:             C
Screenshot:            F12
Map overview:        LCTRL
Drop CTF flag:   BACKSPACE
Fullscreen:              ?
Tell me if I need to tell more about my hardware/software.