I can't put all the code up here - its confidential. But the full code of the sub in question is

sub runQueries
{
    my $LogFilePath = $ENV{"DATALOADFILEROOT"}."/files/";
    my ($thingToDo, $fileHandle, $queriesToRunRef, $queryCodeRef, $dbh
+) = @_;
    # 'queries' is a list of queries we need to run in a certain order
    # 'queryCode' is a hash list of queries, keyed on query name.
    my @queries = @$queriesToRunRef;
    my %queryCode = %$queryCodeRef;
    my $sqlStatement = "";
    my $sth;

    foreach my $query(@queries)
    {
        print $fileHandle "next query is $query\n";
        if (defined $queryCode{$query})
        {
            print "1\n";
            my $queryLogFile = $LogFilePath . $query;
            my $sqlSuccess = 0;
            print "2\n";
            if (defined $queryFiles{$query})
            {
                print $fileHandle "writing to file - $queryLogFile\n";
                open(queryLog, ">$queryLogFile") or return "Couldn't o
+pen $logFilePath . $queryLogFile - $!";
            }
            print "3\n";
            my $sqlStatement = $queryCode{$query};
            my $rowCount = 0;
            print $fileHandle "code - $sqlStatement\n";

            # We put these next statements into a loop because we migh
+t encounter an error
            # we can recover from.   If so, the 'eval' will catch it a
+nd throw it to 'if ($@)'
            while ($sqlSuccess == 0)
            {
            print "4\n";
                eval
                {
            print "5\n";
            #$dbh->{RaiseError} = 1;
            print "6\n";
                    $sth = $dbh->prepare($sqlStatement);
            print "7\n";
                    $sth->execute();
            print "8\n";
                    print $fileHandle "rows affected - " . $sth->rows 
+. "\n";
                    #my $result = $sth->fetchall_arrayref({}); 

                    while (my @row=$sth->fetchrow_array())
                    {
                        if (defined $queryFiles{$query})
                        {
                            print queryLog "@row\n";
                        }
                        $rowCount++;
                    }
                    $sqlSuccess = 1;
                };
                if ($@)
                {
                    print $fileHandle "caught error $@\n";
                    my $errString = $@;
                    print $fileHandle "here err string is |$errString|
+\n";
                    if ($errString =~ m|Table '(.*)' already exists|)
                    {
                        print $fileHandle "got to here\n";
                        my $sql = "drop table " . $1;
                        my $drop = $dbh->prepare($sql);
                        $drop->execute();
                    }
                    else
                    {
                        return "Error found - $errString";
                    }
                }
            }
            if ($rowCount > 0 && (defined $queryFiles{$query}) && $que
+ryFiles{$query} eq "stop")
            {
                return "query '$query' wrote $rowCount rows - this nee
+ds investigating\n";
            }
            if (defined $queryFiles{$query})
            {
                print $fileHandle "Wrote $rowCount rows\n";
                close querylog;
            }
        }
        else
        {
            print $fileHandle "******* NO CODE FOR THIS KEY ********\n
+";
            return "Can't proceed - no code for query $query\n";
        }
        $sqlStatement = "update dataLoadProgress set progress = '" . $
+query . "'";
        $sth = $dbh->prepare($sqlStatement) or return $DBI::errstr;
        $sth->execute() or return $DBI::errstr;
    }
    $sqlStatement = "update dataLoadProgress set progress = '" . $thin
+gToDo . ":Success'";
    $sth = $dbh->prepare($sqlStatement) or return $DBI::errstr;
    $sth->execute() or return $DBI::errstr;
    return "Success";
}
[download]

This sub is kept in a '.pm' file which is called in a 'use' statement in the top-level script. If the top-level script is a command-line module, with no Tkx in it, the 'eval' works properly. If the top-level script has Tkx in it, it dies without going to the exception handler. I say this because the output from all those print statements is: 1 2 3 4 5 6 7 and the print statement in the error handler doesn't show The tkx code is extremely simple. Here it is:

Tkx::package_require("style");
Tkx::style__use("as", -priority => 70);
my $mw = Tkx::widget->new(".");
$mw->g_wm_title("PSC Dataload");
$mw->g_wm_minsize(300,200);
my $Email1;
$Email1 = $mw->new_button(
        -text => "Email1",
        -command => [\&doTheWork,"Email1"],
    );
    $Email1->g_pack(-padx=>10, -pady=>10,);
my $Email2;
$Email2 = $mw->new_button(
        -text => "Email2",
        -command =>  [\&doTheWork,"Email2"],
    );
    $Email2->g_pack(-padx=>10, -pady=>10,);
my $Email3;
$Email3 = $mw->new_button(
        -text => "Email3",
        -command =>  [\&doTheWork,"Email3"],
    );
    $Email3->g_pack(-padx=>10, -pady=>10,);
my $Forms;
$Forms = $mw->new_button(
        -text => "Forms",
        -command =>  [\&doTheWork,"Forms"],
    );
    $Forms->g_pack(-padx=>10, -pady=>10,);
my $LDG;
$LDG = $mw->new_button(
        -text => "LDG",
        -command =>  [\&doTheWork,"LDG"],
    );
    $LDG->g_pack(-padx=>10, -pady=>10,);
my $Load;
$Load = $mw->new_button(
        -text => "Do Data Load",
        -command =>  [\&doTheWork,"Load"],
    );
    $Load->g_pack(-padx=>10, -pady=>10,);
my $Log;
$Log = $mw->new_button(
        -text => "Write Logs",
        -command => [\&doTheWork, "Logs"],
    );
    $Log->g_pack(-padx=>10, -pady=>10,);
$formalityList = $mw->new_button(
        -text => "Write Formality List",
        -command => \&writeFormalityList,
    );
    $formalityList->g_pack(-padx=>10, -pady=>10,);
my $b;
$b = $mw->new_button(
        -text => "Exit",
        -command => sub {
        $b->m_configure(
            -text => "Bye Nora :\)",
        );
        cleanUp();
        Tkx::after(1500, sub {$mw->g_destroy; });
    },
    );
    $b->g_pack(-padx=>10, -pady=>10,);


    Tkx::tk___messageBox(
        -parent => $mw,
        -icon => "info",
        -title => "Tip of the Day",
        -message => "Please be nice!",
    );
[download]

Then there's some preliminaries and initialization, then

#Start the GUI loop
Tkx::MainLoop();
[download]

If I remove that from the top-level program, the eval statement in the 'use' module works.