The same effect was noted here;
http://dotnetfish.blogspot.com/2007/11/expected-identifier-string-or-number.html

IE will report Javascript errors if a setting is selected to debug script. To prevent this, go to IE's Tools > Internet options, then the Advanced tab.

Under the "Browsing" options, tick the two options for;

Disable script debugging (Internet Explorer), and
Disable Script debugging (Other).

See if that helps.

Mark