Do you have any of your own custom javascript? Try removing it and see if you are still getting the error message.
bendewey
2009-03-23 17:11:18
A:
Essentially that was the problem. I was injecting some JavaScript into a page, but I had forgotten to close the curly braces. The problem was actually in a different page and on a completely different line. Nothing to do with MicrosoftAjax.js
ilivewithian
2009-03-24 12:03:03
A:
IE's jscript engine gets very confused if you leave a trailing "," in a list e.g., {a,b,} will create compile errors at locations that have nothing to do with the where the error is. Following Bendewey's is the best course of action - divide and conquer to find the line with the problem.
I assume firebug is using the same jscript engine as IE does. FF and Chrome don't have this problem so that's an additional symptom.
Tony Lee
2009-03-23 17:20:07