ok there are 2 thing that could b the problem, other wise reinstall every thing your TightVNC Server and PortableVNC,

1: in TightVNC make sure in the top right hand corner that remote mouse movment is ON

2: make sure on your PSP that you are in "mouse mode" click "HOME" then click it again (to exit out of home menu) then you will be presented with the PVNC menu of options. Hit the right d-pad button till you see something that reads mouse mode. click on it then you will go back to ur desktop, have funn!

IF THOSE DIDN'T WORK REINSTALL EVERYTHING OR TRY FOLLOWING DIRECTIONS HERE: http://www.i-hacked.com/content/view/195/62/