[Typo3] tt_products: Error in payment Handlescript

[Peer Dicken]

Hi all,

whenever I'm trying to use an handleScript for my payment method, I'm 
getting this error:

Warning: Missing argument 3 for includehandlescript() in 
/htdocs/t3/typo3/ext/tt_products/lib/class.tx_ttproducts_pricecalc_div.php 
on line 55

Warning: Missing argument 4 for includehandlescript() in 
/htdocs/t3/typo3/ext/tt_products/lib/class.tx_ttproducts_pricecalc_div.php 
on line 55
Heres my Typoscript for the payment:

plugin.tt_products.payment {
   10 {
     title = Mastercard / Visacard
     calculationScript = 
fileadmin/templates/xy/scripts/products_comp_calcScript.inc
     handleScript = fileadmin/templates/xy/payment_PayOne.php
     templateFile = fileadmin/templates/xy/payment_PayOne_de.tpl.html
     handleScript {
       merchant = xxx
       currency = 208
       [... and some more values ...]
     }
   }
}


This happens all the time, even if I'm simply including the DIBS 
payment. Any ideas?

Thanks!
Peer