Strange Firefox 3 Error

Version 3.0.3 to be exact.
Error content:

“The page you are trying to view cannot be shown because it uses an invalid or unsupported form of compression.”

Can anybody using Firefox please see if you get the same error (click here) and post results in the comments?
(Please ignore the content on that blog, I’m revamping it for classroom use)
Other browsers seem to be unaffected. Clearing the cache didn’t help. Resetting Prefs didn’t help. Burning joss sticks and mumbling to the Buddha didn’t help.. And I’m not using a proxy. Hmm…
This is very curious: Opening the directory produces the error.
However, specifying the index file does not.
A thread on this error in the Firefox support forum
UPDATE: I just moved over to my laptop; Firefox updated to version 3.0.4 and is having no problems with the link, so… Good. But weird.