Your error is, that you call $query->param('typeofinfo') in scalar context. If you want a list ask for a list ;-).
This example check 1 and 4. 
use HTML::FillInForm;
use HTML::Template;
use CGI;
my $query = CGI->new;
my $html = <<__TEMPLATE__;
<input type="checkbox" name="typeofinfo" value="1" /> Program<br />
<input type="checkbox" name="typeofinfo" value="2" /> Abstracts<br />
<input type="checkbox" name="typeofinfo" value="3" /> Exhibits<br />
<input type="checkbox" name="typeofinfo" value="4" /> Registration<br 
+/>
__TEMPLATE__

my $fillinformvalues = { typeofinfo => [ 1, 4 ] };
my $form = new HTML::FillInForm;
my $page = $form->fill(
   scalarref  => \$html,
    fdat        => $fillinformvalues );
print $page;

[download]
Boris

In reply to Re: Can HTML::FillInForm handle multiple checkboxes? by borisz
in thread Can HTML::FillInForm handle multiple checkboxes? by bradcathey

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