Did you read post #8? Try changing the zuluCrypt mainwindow from ApplicationModal to WindowModal and check the behavior.

Quote Originally Posted by mhogomchungu View Post
This could be a Qt creator 2.3.1 + Qt 4.7.4 specific issue
Don't think so. I'm using QtCreator 2.2.1 & Qt 4.7.3 (64 bit).

Try it from the command line:
mkdir systraytest && cd systraytest
touch main.cpp
open main.cpp with your favorite editor and paste in the code. Save
qmake -project
qmake
make
./systraytest

Again, it works fine on a Debian Sid (KDE) box.