- check cache in preferences and note that the 'empty disk cache' button is disabled
i don't think i've ever looked at where the root was for the disk cache folder so i can't be sure but, at least after the upgrade, it's set to 'user/library/caches.' that means ae itself creates the version-specific branch to the actual cache ('adobe/after effects/14.1'), which makes it impossible to point ae to the old cache under the 14.0 folder in order to enable the clear cache button in the application.
anyway, clearing the old cache manually does the trick just fine. wanted to share in case anyone is also having this trouble.