Eclipse error constantly pops up while editing Javascript

Question

I am working on relatively small (100-300 lines) Javascript files in Eclipse and periodically it gets really upset about some piece of code and pops up this error every time

Answer 1

An even better answer (from the bug report linked by Cliff Ribaudo, comment #10 and others):

Turn off Toggle Mark Occurrences (Alt-Shift-O or the paintbrush icon on the toolbar, which handily, will show you your current state).

Thanks Cliff!

Edited: