Firefox: (...)unsupported form of compression

Using Firefox 5.0 I noticed that in a webpage some javascript was not running.

Using Firebug I noticed that the call to related .js file was returning the following error:

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

Because the page (and javascript) was working in other browsers I tried the "force-refresh" ("do not use cache") and it fixed the problem! It looks like the cache was corrupted somehow.

Now I know!

BTW: I'm thinking in switching to chrome as my default browser. Any thoughts?