This happens every time I open arduino consistently and each time I use the menus. The board and serial ports sub menus come up as just a line for each. I go to the next menu ,"Help" drop it down then move back to the "Tools" and it has fixed itself and the sub menus appear.
When I first drop down the File menu Sketchbook is written over Close and Examples is written over Save. When I move to Edit and then back to File it has righted itself .
Do you know about this ? I searched and found no mention of it .Read the troubleshoot too Using Linux and Arduino Version 1.0.1