I recorded using a small recording device with a line-in. So I just connected the headphone of the UR22 to the recording device line-in and recorded both versions. They are therefore recorded in the exact same way.
However I also hear that the “bad” recording is mono and been doing some research. The Roland UA-22 is quite similar to UR22 but have a stereo / mono / off switch for monitoring:
http://www.rolandce.com/mediafiles/images/products/large/DUO-CAPTURE_EX_R_300_TMP.jpg
I think this is what I am missing. The UR22 simply monitors in mono, not stereo I think.