But what makes it all far, far worse is that IE6 and IE7 can sometimes produce error messages which, as is usual for those browsers, contain no useful information whatsoever.
Here's a recent example:
Error: Expected identifier, string or number
It's sometimes a little too strict to be useful, complaining about implicit global variables (even when that variable is called
window). My suggestion is to ignore those reports, though; but watch those commas!