11R crashes after use with MacBook and Dell laptop

Hi everyone, I have a strange problem with my 11R (sorry if this has been handled before!). Whenever I plug it in my MacBook (from 2009, iOS 64bit, same thing with a Dell laptop) to edit the sounds, it works fine. Only until I switch it on again (like the next day for instance). Then it's dead, it lights up but no sound. I have to make a memory reset to get it to work again. With my iMac I do not have this problem (the MacBook and the iMac have the same iOS!). Any advice would be welcome cos I use my MacBook live to edit the sounds. I own two 11Rs, both show the same problem! Thanx a lot in advance!