Error indicates to me that it is a problem with your $dbh not being initialized

Thanks injunjoel! You were right. It had nothing to do with my prepare statement. And I was testing with  || die $DBI::errstr; but it wasn't turning up anything different than my use warnings; use CGI::Carp qw(fatalsToBrowser); was. I feel badly that it had nothing to do with the prepare but did I ever learn a lot about placeholders from replying monks. Thanks again for the nudge injunjoel and to all monks.

Update: don't know how my reply to injunjoel ended up here. But apologies.