Good suggestion, I just tried it. Here is the modified program:

#!perl -Tw

use strict;

use DBI;
use Win32::OLE;
use XML::Generator;

my $list_id = '40000-1022206382';
my $request_id = 1;

# Be paranoid about error messages
Win32::OLE->Option(Warn => 3);
    
# Start the Processor
my $connection = Win32::OLE->new('QBXMLRP.RequestProcessor');
    
# Name your program
$connection->OpenConnection("qbtmr", "Timer Import");

# Open the currently open QuickBooks file, in "DoNotCare" mode.
my $ticket = $connection->BeginSession('', 2);

my $dbh = DBI->connect("DBI:CSV:") 
    or die "Cannot connect: " . $DBI::errstr;

my $sth = $dbh->prepare("SELECT Customer, Service, Duration, Date FROM
+ data")
    or die "Cannot prepare: " . $dbh->errstr();

$sth->execute() or die "Cannot execute: " . $sth->errstr();

$sth->bind_columns(\my($customer, $service, $duration, $date));

my @items;

while ($sth->fetch) {
    push (@items, {
        date    =>    $date,
        customer=>    $customer,
        service    =>    $service,
        duration=>    $duration
    });
}
$sth->finish();
$dbh->disconnect();

foreach my $item (@items) {
    my $gen = XML::Generator->new(
        escape        =>    'always',
        conformance    =>    'strict',
        pretty        =>    2,
        dtd            =>    [ 'QBXML', 'PUBLIC', "'-//INTUIT//DTD", "
+QBXML QBD 1.1//EN'"],
        version        =>    '1.0'
    );
    
    my $xml = $gen->xmldecl;
    $xml =    $gen->QBXML(
        $gen->QBXMLMsgsRq(
            {'onError' => 'stopOnError'},
            $gen->TimeTrackingAddRq({requestID => 1},
                $gen->TimeTrackingAdd(
                    $gen->TxnDate($item->{date}),
                    $gen->EntityRef(
                        $gen->ListID($list_id)
                    ),
                    $gen->CustomerRef(
                        $gen->FullName($item->{customer})
                    ),
                    $gen->ItemServiceRef(
                        $gen->FullName($item->{service})
                    ),
                    $gen->Duration($item->{duration}),
                ),
            ),
        ),
    );
    my $xml_req = $gen->xml($xml);
    
    $request_id++;
    
    open (CHANGE, ">change.xml") or die "Can't open change.xml for wri
+ting - $!";
        print CHANGE $xml_req;
    close CHANGE;
    my $xml_res= $connection->ProcessRequest($ticket, $xml_req);

}
# Gracefully end everything
$connection->EndSession($ticket);
$connection->CloseConnection;
[download]

Contents of change.xml. It is precisely the same as actual.xml and reinvent.xml. I've verified this using "Beyond Compare" and then again after using diotalevi's regex.:

<?xml version="1.0" standalone="no"?>
<!DOCTYPE QBXML PUBLIC '-//INTUIT//DTD QBXML QBD 1.1//EN'>
<QBXML>
  <QBXMLMsgsRq onError="stopOnError">
    <TimeTrackingAddRq requestID="1">
      <TimeTrackingAdd>
        <TxnDate>2003-01-01</TxnDate>
        <EntityRef>
          <ListID>40000-1022206382</ListID>
        </EntityRef>
        <CustomerRef>
          <FullName>Cahoots Sports Bar &amp; Grill</FullName>
        </CustomerRef>
        <ItemServiceRef>
          <FullName>AP</FullName>
        </ItemServiceRef>
        <Duration>PT00H01M</Duration>
      </TimeTrackingAdd>
    </TimeTrackingAddRq>
  </QBXMLMsgsRq>
</QBXML>
[download]

Same exact error message. But your suggestion got me thinking. So I modified the program in this post by moving all the Win32 connection crap (between the request_id and the start of the dbi stuff) to right before the foreach loop ( my goal to make all the dbi stuff happen first and the QB stuff happen second) and ran it again. XML came out exact, again. And the error message still happened.

Tough one this - Just to confirm, when you comment out the db stuff and use

push (@items, {
        date    =>    "2003-01-01",
        customer=>    "Cahoots Sports Bar & Grill",
        service    =>  "AP",
        duration=>    "PT00H01M"
    });
[download]

it all works OK ?
poj