I was afraid someone might say that. I spent time a while back investigating how Plesk was utilizing MSFTP. I really consider this a substantial loss of productivity in my operation. I will figure out a work around possibly an SFTP server running secondary.
Since Plesk 7.6 IIS will be revert back to IIS 6 mode when you perform any operation on domains.
Workaround on this will be, third party ftp server running on another port