Hi Tim,
I have installed proftpd-mysql ...
I do not know the answer. On Centos 5.x I use as FTP sever the standard server VSftp. It has always worked problemlessly. For client I use Filezilla. That too just works.
I do not understand why you are involving 'sql modules'.
Are you trying to transfer MySQL data to a remote server?
I use SSH (I think it is) from with Gnome to transfer some date between servers.
Best regards,
Paul Centos 5.3, 5.4, 5.5 and 5.6 with VSftp, FileZilla, MySQL etc. - They just work for me.