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 I place the cursor on that line. The error is:

'Requesting JavaScript AST from Selection' has encountered a problem.  An internal error occured during "Requesting JavaScript AST from selection".  java.lang.NullPointerException 

While I am converting this:

if(p){     // enter code here } else { return false; } 

into this:

if(p){     // enter code here } return false;  

the error pops up several times. Each time it stops my typing and requires me to click the okay button. I then type two more characters and the error appears again.

Any ideas how to either prevent the error or disable whatever Javascript AST is?

This is on Eclipse Java EE, Indigo Service Release 2. It is almost a flat install, only two plugins installed and neither are for SVN and have nothing to do with Javascript.

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: