Some RedHat advice?

[Neil Schelly]

I've found the solution on my own - thanks for the help from those who
offered.  For the curious, essentially, vsftpd has an option called
"session_support" and doesn't process PAM session modules unless this is
enabled.  In every documentation and FAQ I've found, it's enabled by
default and it wasn't disabled here, but I guess it's plausible that the
Red Hat distribution compiles that with the opposite default or something.
 I set it to YES and it's just working now.