This was a prblem before (Joe verified it on my server), and after I found a fix, implemented it, and it worked fine, it stopped after the last few updates.
Essentially, ftp again does not work, does not authenticate, and thus the entire virtual server situation has just become unusable.
It would seem that there is again something with the PAM module. The last update cycle updated virtualmin, as well as broought along a kernel update (not sure if that's relevant).
If you need to pop into my server to verify, please let me know - hzink at mac dot com
Seriously, though, this really needs to get fixed... a server is useless if you can't put things on it.