Parsing tld files takes progressively longer each time

I've been making many small modifications to my project/module settings.
I noticed that every time I click OK in the project roots dialog, Idea
reparses a few files, including some .tld files in external libraries.
For example, I have the faces libraries in my project, and idea will
reparse the faces tld in that jar every time I click out of my project
roots settings.

I also noticed that:

a) It takes a long time to parse each tld, and
b) It takes far longer each time it's parsed within a single Idea session

By around the 5th time, idea grinds away for about 5 min, then freezes.
So I have to restart. After restart, parsing the tlds goes back to just
10 seconds or so. Rinse and repeat. Anyone else noticed this?