Why floating letters left behind from workspace pull-down App menu?

The Matlab window appears to generate floating letters in the Windows workspace. The following letters appear where the Matlab window toolbar has a the following App pull-down menus: G et more apps, I nitial App, and P ackage App. Even if the Matlab window is moved, the letters remain in the Windows workspace. Any idea what could be causing this?

[Sean de Wolski]

Screenshot?