One Friday afternoon I called at Office Partner and the nice woman at the other end of the line told me that it could be that the chip is defective on the cartridge and that one sends me two new cartridges. The cartridge went on the same day out, were on Tuesday there and were also recognized by the printer immediately.
With the quality of the ink I after the first test more than satisfied. At least I can not see any big difference in quality to the original cartridges.
Conclusion: Good quality, reasonable price and great service. What more could you be? :)