Eclipse error constantly pops up while editing Javascript

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.

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:

At first I thought this was just a trick, but it is working so well, I had to post it as an actual answer.

When the error window pops up, don't close it. Just drag it off to the side, focus back on the main window and keep editing.

When the error happens again Eclipse doesn't change the focus back to the error message. Focus stays in the editing window and you can continue to edit the document.

Likely an eclipse bug. See this thread:

https://bugs.eclipse.org/bugs/show_bug.cgi?id=359005

There is a patch posted there which you might try.

Ironically, the solution for me was to install another plugin. After I installed VJET, and set up my JavaScript project to be a VJET-enabled project, the issue went away.

just replace the xml in your .project file (which lies in home directory of your eclipse workspace .

<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
	<name>your Project Name</name>
	<comment></comment>
	<projects>
	</projects>
	<buildSpec>
	</buildSpec>
	<natures>
	</natures>
</projectDescription>

I've been getting this error lately. I am writing Groovy scripts. The fix for me was to update the Groovy plugin.

I was getting same error with gc overhead limit exceeded description in details section of error. To take action on it I have added following in configuration and issue resolved.

Xms512m
Xmx2048m

Ref: GC overhead limit exceeded problem

In short, for me it was eclipse memory problem.