problem with the different vst's

while i’m trying to control the simple option on any vst on my program i can’t seem to control it with my mouse.
usually, i know i can control it by clicking it and moving the mouse up and down to change the values, but it doesn’t work. instead i need to roll it with the roller on the mouse, or enter the value i need by hand.
maybe someone knows what can i do to change it.
thank you

Sounds like the menu bug afflicting most vst’s. Hopefully it will be fixed next time around and let’s hope it is soon. There are some other threads relating to it.

im not sure i understand.
is it a common problem?