Bill print error

Hi.
I encountered a problem while trying to print a bill in pdf format from Bills page. It seems that html to pdf converterd find html tags closed in wrong order.
I fixed the bug changing the code in ObjectDetail.php from


} else if (substr($col, 0, 5) == '_spe_') { // if field is _spe_xxxx, draw the specific item xxx
$item=substr($col, 5);
if ($internalTable) echo '<td>';
else echo '<tr><td colspan=2>';
echo $obj->drawSpecificItem($item); // the method must be implemented in the corresponidng class
if ($internalTable) echo '<td>';
else echo '</td></tr>';

to

} else if (substr($col, 0, 5) == '_spe_') { // if field is _spe_xxxx, draw the specific item xxx
$item = substr($col, 5);
if ($internalTable) {
if ($internalTable % $internalTableCols == 0) {
echo '</td><td>' . $cr;
$internalTableCurrentRow++;
} else {
echo '</td><td>';
}
} else {
echo '<tr><td colspan=2>';
}
echo $obj->drawSpecificItem($item); // the method must be implemented in the corresponidng class
if ($internalTable) {
// echo '<td>';
} else {
echo '</td></tr>';
}

I'm not sure that this changes are safe for all usages of the module.
Best regards