Finding out what IE was so upset about wasn’t fun, as I didn’t have a debugger for IE. So I started looking for one. Not wanting to install visual studio just for that, I installed(*) “Microsoft Script Debugger”, which is one old piece of software. It’s so old that its readme states that it works with IE 4. At least it works. It lacks watches and some other features you’d expect from a debugger (which Firebug has!), but it got the job done. Mostly.
I wasted about 40 minutes on that issue.
* Installing “Microsoft Script Debugger”, contrary to what some my tell you, does not require installing old office versions. I followed a download link on Microsoft’s website, and got it. It does require some voodoo if you’re running Vista, but nothing too hard to handle.