[Dovecot] PostLogin Scripting issue

Trying out the post-login scripting Timo added recently. Wanting to run a SQL query, as detailed in the example on the Wiki.

However, my "USER" env variable is set to "OK" instead of the username.

DOVECOT_VERSION=1.0.rc16 RESTRICT_GID_FIRST=127 USER=OK

All the other variables (MAIL, HOME, etc) are fine with the correct username.

Am I missing something obvious?

Thanks,

-c