When I run SQL Developer 4.1.0.19 it sometimes freezes and not repaint graphical user interface.
I also noticed that writes too much (500MB) in LOG File: SQLDeveloper_20150602092025.log
All is the same message SEVERE
SEVERE 129 0 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 130 218 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 131 26507 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 132 31 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 168 40517 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 179 5164 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 182 3838 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 183 10016 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 184 702 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 185 10390 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 186 31 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 187 281 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 188 11482 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 189 16 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null
SEVERE 190 2995 oracle.dbtools.raptor.backgroundTask.RaptorTaskManager$1 null