OS 10.5 - OS X (10.5.2) and split/dual screen weirdness

Hi All;

I have a macbook running OS X 10.5.2

I can plug in an externam monitor and get the dual monitor thing going (not mirrored). However for any window on the external monitor if I right click with the mouse the resulting pop-up menu always shows up over on the laptop monitor.

Anyone know how to fix this ?

Thanks in advance