When using the task switcher (alt-tab or alt-$), PCGen is referenced as pcgen-core-Main. GMGen is also referenced with a class based name.
This page (http://locademiaz.wordpress.com/2011/08/30/turn-your-java-apps-gnome-shell-friendly/) evokes the problem and propose solutions.
This fix the problem. It needs to be tested under other operating systems, mainly Windows & MacOS ; I believe it will produce a warning.
Yep, a warning is thrown on Windows. It could be avoided by a SystemUtils.IS_OS_WINDOWS escape from the setupApplicationTitle method.
Send me your source forge id I'll give you commit access.
Fixed by changing the name.