V1.0.3 is out now, might be worth updating to see if the issue is still there. http://www.nanoloop.de/update/nlmono103.gb

Working in Nanoloop Mono, v.1.0.2, I discovered something odd with the click channel.

Having made a nice, growly sound on channel C by, among other things, maxing out the FM amount, I find it impossible to silence the channel by selecting either an empty, unused slot or slot 0. Doing so leaves growly  static filling the channel. It is possible to remove the static by selecting a slot containing a sequence (and thereby since the channel by selecting a slot contains a sequence with the volume dialed to minimum).

Reducing the FM amount on the click channel also allows a selected empty slot or slot 0 to silence the channel. Attempts at lowering the FM amount the choosing an empty channel leaves the static at a lower volume, until, at a point with sufficiently low FM amount, it ceases to appear.

Anyone else encounter such a quirk? It can be lived with (and perhaps embraced with time), but if someone was to says that it's a simple matter of dirty contacts, I would be happy. 

Screenshots (and possibly video) available if required to help explain the cryptic text.