I had problem with the clamp on mine - intermitent problem with it not biting enough to hold bike. Emailed importer got nowt back, contacted Minora in Japan and States and got advice which wasn't helpful.
Sent it back and got a deal on a Park one which is great.
I'm sure there was something simple I could have done to make the minoura one work but why should I faff on with it when I could simply get a Faff free model for only 10 quid more.