[EvilLS1]

Christian,
Check and make sure that you added this bit of code to profile.php:

// ############################### EDIT VEHICLE PROFILE #######################
if ($_REQUEST['do'] == 'edittimeslip')
{

  if ($bbuserinfo[userid]==0  or $bbuserinfo[tdban]==0) 
{
	print_no_permission();
  }


	unset($tempcustom);
	exec_switch_bg();
	// Get Custom profile fields
	$customfields = array();
	fetch_timeslipfields(0);

if ($vboptions[allowtimeslipupload]){
		$timeslippic = $DB_site->query_first("
			SELECT userid, dateline
			FROM " . TABLE_PREFIX . "customtimeslippic
			WHERE userid = $bbuserinfo[userid]
		");

		if ($timeslippic)
		{
			$timeslippicchecked[1] = HTML_CHECKED;
			$timeslippicchecked[0] = '';
		}
		else
		{
			$timeslippicchecked[1] = '';
			$timeslippicchecked[0] = HTML_CHECKED;
		}		
}

	// draw cp nav bar
	construct_usercp_nav('vehicleprofile');

	$navbits[''] = $vbphrase['edit_timeslip'];
	$templatename = 'modifytimeslip';
}
// ############################### start update ###############################
if ($_POST['do'] == 'updatevehicleprofile')
{
	
  if ($bbuserinfo[userid]==0  or $bbuserinfo[tdban]==0) 
{
	print_no_permission();
  }
        $userfields = verify_vehiclefields(0);
	// insert custom user fields
	if (!empty($userfields))
	{
		$DB_site->query("UPDATE " . TABLE_PREFIX . "userfield SET userid=$bbuserinfo[userid]$userfields WHERE userid=$bbuserinfo[userid]");
	}
if ($vboptions[allowtimeslipupload]){

	globalize($_POST, array('timeslippic' => INT, 'avatarurl' => STR));

	if ($timeslippic==1)
	{
		require_once('./includes/functions_upload.php');
		process_image_upload('timeslippic', $avatarurl);
	}
	else if ($timeslippic==0)
	{
		$DB_site->query("DELETE FROM " . TABLE_PREFIX . "customtimeslippic WHERE userid = $bbuserinfo[userid]");
	}
}

$url = "timeslips.php?$session[sessionurl]";
	eval(print_standard_redirect('redirect_updatethanks'));

}

If it still doesn't work, check the spelling of the template name and the contents of the modifytimeslip template.