Proftpd doesn't update last log properly

[Anders Gulden Olstad]

FreeBSD  6.2-RELEASE-p8 SPARC64
Ports: proftpd-1.3.1_2

I have a small annoying problem with my proftpd installation. It doesn't
update the last log properly. All logins are
left as "still logged in" with Jan 1 as date.

All other logins are correct, except ftp.

  user         ftp      192.168.1.10     Thu Jan  1 01:00   still logged in

I've testet it in both FreeBSD jail and directly on host. Same result.