Debugging, BASE, Opera and XHR

I've been going crazy trying to make my new ajaxy review creation tool cross-browser. It isn't working out at all. IE gets stuck and gives terrible, totally non-helpfull debug information. A line number, but it won't even specify the script it happened in, or what kind of error it was. Terrible, and I can't find anything on debugging in IE, a plug-in like firebug would be nice.

I also found out, that as of Opera 9.10, it does not apply the BASE tag to script requests. I don't know if that's spec or not, but I had to apply absolute paths to a bunch of XHR's to get them working in Opera. That one took a while to find, but I found the debugging stuff for Opera, and it's not terrible.

I haven't even thought about Safari, I'm kind of scared of it actually. Right now I'm going with a second set of scripts that don't use all the fancy stuff in them, and I'm using %{HTTP_USER_AGENT} and mod_rewrite to push browsers to the right place.

Good times.