SRM Procurement - Problems with article inserts

Hi friends,

I have following problem with SRM Procurement:

If you choose a second product from a catalog, the system inserts the first article in the second position and not the second one that you choose.

Details:

I purchase the first article in a catalog.
In my shopping cart list, I click on the shopping cart to display it. Here I click on “Edit” and “Add item” to choose an article from a catalog.

Now, the system inserts the second position in the first article and not the second one I have chosen. But the vendor is correct.

What could bethe reason for this?

Thanks in advance for any help!

Browser: Internet Explorer 9.0.8 and Firefox 34.0.5
SRM 7.0 EHP 2 (Standalone)