I've noticed that the PicoScope occasionally become unresponsive. In manifests in the way that it just stops receiving data. There is no indication that it has occurred, the only way to notice is that there is no new data presented by the software.
This is particularly annoying if you are waiting for a trigger, as the software does not indicate that the PicoScope has become unresponsive, so you end up waiting for the trigger to happen, when it has already happened; you just didn't see it.
I checked the system's log, but can't find any interesting. I have seen occasions where I got a system notification saying that the PicoScope was disconnected due to excessive current consumption (although running on DC from wall). Not every time though.
It's a pretty annoying issue, and I'm sorry I can't provide more details about the problem. I will use the PicoScope extensively on my Mac the coming days though, so if you wish me to try something, please tell me.
Update: I've noticed that this primarily occur if you are doing measurements for a long period of time (i.e. collection time set to e.g. 50 seconds or longer)
MacBook Pro (mid 2009)
OS X 10.9.4
2.26 GHz Intel Core 2 Duo
8 GB 1067 MHz DDR3
NVIDIA GeForce 9400M 256 MB