latest virtualmin - Failed to create virtual server, bad file descriptor

"Failed to create virtual server : Failed to open /home/user/.usermin/mailbox/inbox.imap for writing : Bad file descriptor" <- I get this error lately, after upgrading virtualmin, webmin and usermin to latest versions (GPL).

Operating system FreeBSD 6.2
Webmin version 1.400
Virtualmin version 3.52.gpl (GPL)

Dont know where to look for a workaround, no errors in logs..

Status: 
Closed (fixed)