StarOffice needs a replacement for the default awt toolkit. This replacement toolkit inherits from java.awt.Toolkit, where it has to overwrite getSystemEventQueueImpl. Using the java.awt.EventQueue it can not post events, because there is a hardcast from java.awt.Toolkit to SunToolkit in the EventQueue implementation at line 99.
This cast was introduced in 1.2.2 as bugfix for 4171596.

--- see also Comments.