UR22 missing samples issue

Hello everyone,
This is my second UR22 unit and I find a very disturbing problem.

I have some missing samples randomly in different recording.
In the first unit I bought (Mark 1) I thought the issue was with the phantom power in the machine so I replaced it with Mark 2, but now I’m still experiencing the same exact issue in any recording, guitar, microphones etc.

Every few minutes, randomly in different positions in the recordings (sometimes none, sometimes two or more times in a 3-min recording) I have a ‘tick’ or ‘pop’ kind of sound which is a missing sample.

I use Logic Pro X, and my system (MBP late 2011) runs on an SSD, 8GB RAM, i7 quad-core.

Here are the photos (first 3 are guitar recording, last one is microphone):
http://imgur.com/a/0jTHy

Here’s an audio sample of the guitar issue shown in the picture:
http://vocaroo.com/i/s180jJYfFPfA


Any thoughts would be welcome.