This issue can be caused by an extension that isn't working properly.

• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Start Firefox in Safe Mode to check if one of the extensions or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance/Themes).

• Don't make any changes on the Safe mode start window.
• https://support.mozilla.org/kb/Safe+Mode

Thanks. I know that.

Is there an answer to my question though...is there an extension that will issue the stop command whenever the error appears?

If it does work in Safe-mode then disable all extensions and then try to find which is causing it by enabling one at a time until the problem reappears.

• Use "Disable all add-ons" on the Safe Mode start window to disable all extensions.
• Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit")

I guess no one is going to answer the question I asked--instead, trying to steer me into the troubleshooting YOU prefer.

I will try one last time: is there an extension that will issue the stop command whenever the error appears? If you do not want to answer this question, no need to respond.

NO, there is no such extension.

Issues like these can be caused by a malfunctioning extension.
If the name of the offending script is mentioned then that can give a clue.

Is it always the same script that is causing the problem?

OK, thanks for the info that there is no such extension. Wish there was. Searching about this, there are hundreds of posts about it, so it is a common issue. Interestingly, stopping the script NEVER has any adverse effects; that's why I was hoping to find an auto-stop extension.

I have set the dom.max_script_run_time time out to 30 (no effect) and to 0 (no effect).

The name of the script is not mentioned. I don't think it is the same one because it happens on different pages randomly.

I have looked in the error console. No help--there are tens of entries.

Just happened again...

Error at bottom of list (latest time is
Timestamp: 7/4/2012 10:44:33 PM
Error: GA_googleFillSlot is not defined
Source File: http://forum.xda-developers.com/showthread.php?p=28300803#post28300803
Line: 8009 

page source...

<!-- google adsense code -->
<!-- ca-pub-2900107662879704/NewForum_InContent_728x90 -->
<script type='text/javascript'>
GA_googleFillSlot("NewForum_InContent_728x90");
</script>
</td>
</tr>
</table>
</div>

Another one at a different time today... Timestamp: 7/5/2012 12:17:09 PM Error: loadAdVals is not defined Source File: http://drudgereport.com/ Line: 578

PAGE SOURCE: