Window grouping in SuSE almost drove me nuts.
Under OpenSuSE 11.3, the window grouping function seems partly broken. If activated multiple windows of the same application (like multiple instances of okular or the main window and the data window of pgadmin3) are put into a single window and a small tab bar is added above the title bar.
Switching windows with that tab bar doesn’t always work and if the application is currently in the background, it is often impossible to bring the app window back onto the screen by clicking it in the task bar.
To disable this, goto Start > Personal Settings. Make sure the General tab is selected and click Appearance under Look & Feel. Then selects Windows and uncheck Enable window grouping.