[RWP] reaper 4 sampler problem!!

[trahern culver]

hey all i'm running the latest version of reaper4 on windows 7 when i tried to use the sampler plug in the other day i could load in samplers just fine but when i went to try an change the sustain release and other attributes the courser would jump to an other area of the screen before i could make the changes i wanted to make any one know what the problem is? 

your help with this problem would be most welcome kind regards trahern.