Bad design

It's all nice and well to have the rain water being collected from the roof and being taken further from the house to keep foundation dry as below:

The only issue I stumble upon was that I bought relatively expensive Uponor Down Pipe Gutter Plus (Rännikaivo Plus), which should fit on top of the standard water collector of 110mm. The problem, which I noticed only when it started raining, is that the water instead of going smothly into the pipe it starts leaking next to it. This is because of the stupid design of this Uponor piece (for which I am sure there is an explanation :)).

I went to K-rauta and told about my problem and then seller said many people complained about the issue but nothing happens (at Uponor, he meant). The interesting solution was to put a middle piece in between of the type as below:



Other people seem to have noticed this issue as well. See http://keskustelu.suomi24.fi/node/1263964 (in Finnish).

With this piece in between there is almost no leak.

Maybe is time for Uponor to design their gutter pipes to fit perfectly on the 110mm pipes without the need to buy another piece in between.