A few users have reported that after some time the UI in DbVisualizer gets corrupt whereas components are multiplied and rendered on top of each other, making the UI impossible to navigate and use.
Similar problems, such as slow UI, has been reported when running DbVisualizer on Windows as a VMWare Fusion Guest OS.
The following Java system property has been reported to resolve the issue:
-Dsun.java2d.d3d=false
Insert the setting in a new row in Tools->Tool Properties and in the General tab under Specify Overridden Java VM Properties here text field.