What is this new "l2schemas" folder?

After I installed SP3 for XP (I'm running the Home Edition), I noticed a
new folder: c:\windows\l2schemas

My copy of Firefox 3 started doing weird things after a while (fields
were the wrong size on websites like Google, so I couldn't enter search
terms). After trying several other tactics (rebooting, reinstalling FF3,
etc.) I backed up and deleted the l2schemas folder and the problems with
FF3 went away. Then, I restored the folder, and strangely enough the
problem didn't come back.

I've looked and looked to find out what this l2schemas folder is
supposed to be for, but can find absolutely NO information about it. I
detest and hate not knowing what something on my system is for. Can
anybody please explain this folder?

TIA.

--
John Corliss