Dear Magento experts, users, shop owners and anybody of the same interest and believe in Magento :-)
We are using Magento 1.9 on a Debian Linux machine with Apache 2.41, PHP Version 5.6.
We tried to configure a voucher for
- logged-in / registered customers
- one certain article, based on SKU selection
- giving a in time limited special price minus 20 percent
Everything works fine, BUT only for exact ONE SINGLE article.
However we tried to combine this special offer with other conditions the response of the system was "voucher not guilty".
What's even more curious is, that the voucher has not been accepted for more than one of the same sku (amount = 2).
We already debugged the code 
more than once and do have the impression that there might be a bug within the core.
We are also sure that this mistake is not related to a hash-value error.
Please make any comment if you have any idea that could help.
Thanks in advance!
Yours, informixx