I had that problem also with Title, due to a seperate addition I'd made to the Users table. I had this problem a while ago so I'm not sure if this is right or not...but I assigned an extended Title/Username within the sub &site_html_link, it looks kind of like this:
Code:
my $user = {};
defined $dynamic and &load_user ($dynamic, $user, $rec->{CategoryID});
my $output = &load_template ('link.html', {
detailed_url => "CUT TO FIT",
%$rec,
%$user,
%GLOBALS,
LinkTitle => $rec->{Title},
enc_title => CGI->escape ($rec->{'Title'}),
enc_One800 => CGI->escape ($rec->{'One800'}),
enc_add => CGI->escape ($rec->{'Address'}),
enc_town => CGI->escape ($rec->{'Town'})
}, undef, $template);
# Don't clean output on a single link.
return $output;
Truthfully I can't remember what else I did to make this work...but I do remember I had it working.
So what you can do is just reassign a new code like User_Namensie => $rec->{Username}
then access <%User_Namensie%> in the template.