"Wrong password" error: str='dir'

I'm getting an error on a new install I'm finding it impossible to
track down. I'm not seeing any errors in any logs, just the "Wrong
password" error on the cgi login screen.
The hint in the HTML source is just

Username [email protected] not found in system.
str='dir'

I'm following Bill Shupp's toaster install, the following is the
configure I've used.

./configure \
  -t /home/www/cgi-bin/tmda.cgi \
  -p /home/vpopmail/bin/vchkpw \
  -m single-user \
  -l "vpopmail1 /home/vpopmail/bin/vuserinfo ~" \
  -i /usr/local/tmda-cgi-0.13/ \
  -d /display

Any advice on how to track down errors would be greatly appreciated.

Thanks!