Yup i had that too after the upgrade from 2.4.0.0 to 2.5.0.0
The only solution that helped me was to do a clean install
After the clean install it would install properly but am unable to use the maximize window button. It gives me a white screen and the program freezes in an infinite loop.
Luckely it didnt save the windowsize settings so i could restart it and use the edges of the window to enlargen it to 'windowed' full screen.
running on XP sp3 with Shareaza 2.5.0.1