IAT seems to slow down this web page a lot (~30 seconds)

I'm a huge fan of It's All Text. However, it seems to cause a huge slowdown with a web site I use all the time: the "Query" page of the CasJobs database for the Sloan Digital Sky Survey:
http://skyservice.pha.jhu.edu/casjobs/SubmitJob.aspx
(unfortunately, this requires a (free) registration to login).

With IAT disabled, the page loads quickly. With IAT enabled, it seems to begin loading, then I get the dreaded Mac Happy Beachball of Death spinning for 20-30 seconds, and then the page finally loads.

I don't know what information I can provide to help tracking this down. (I also understand that this is a very obscure web site so fixing it is not going to be a priority!)

Sometimes I get the "Unresponsive script" dialog box, complaining about:
Script: chrome://itsalltext/content/cacheobj.js:206
or
Script: chrome://itsalltext/content/cacheobj.js:843
or other places.

Firefox 23.0
MacOS X 10.8.3
IAT 1.8.1

Here is a screenshot when I use the "profile" tool of the Firefox "Web Developer" tools.


Thanks for any help you can provide. I am also reporting this to the CasJobs team and will let you know if they have anything to say.
--dustin