Perl mechanize script no form defined - forms

Question

I'm getting an error No form defined at cqSubmitter.pl at line 33 which is the second set_fields method. Other times I get an Error POSTing http://micron.com Internal Server Error at line 39 , which corresponds to the last click_button line.
I'm not really sure what's going on, and why it's saying no form defined? The first half of the code which includes the first click_button method works fine and saves the correct page, but when I try set_fields for the second time, it errors out.
Anyone familiar with the Mechanize package realize what's going on here?
use Data::Dumper;
use HTTP::Request::Common qw(GET);
use WWW::Mechanize;
#Prepopulated information
my $types_ = "";
my $dept_ = "";
my $group_ = "";
#Create new WWW::Mechanize object
my $mech = WWW::Mechanize->new( 'ssl_opts' => { 'verify_hostname' => 0 } );
my $url = "http://f2prbrequest";
#Fetch URL or Die Tryin'
$mech ->get($url);
$fname = "user";
$pswd = "password";
#Login to ClearQuest form using credentials
$mech->set_fields(
USER => $fname
,PASSWORD => $pswd
);
$mech->click_button(
name => 'Submit'
);
#Set fields and actually fill out ClearQuest Form
$mech->set_fields(
types => $types_
,dept => $dept_
,group => $group_
);
$mech->click_button(
name => 'submit1'
);
$mech->save_content("clearQuestFilled.html");