[bug] advanced cache can't be disabled

I have turned off FC's advanced cache subsystem in FC's config modal window.
Cache is also turned off Joomla-wise.
In spite all this, FC's cache keeps working and, what's worse, i can't seem to flush it. Apparently it is cleaned, but the frontend display tells a different tale.
With cache running, it is nearly impossible to monitor changes.

Environment:
Joomla 1.5.15
FC 1.5 beta5