I tried PicoScope 6 Beta, and the original failure no longer occurs, but it does some other weird things.
If I have the scope actively taking traces, then when the computer goes to sleep, it waits a few seconds, then appears to wake up again, restarting the trace. That is OK, you only miss a few seconds of sweeps, which in most cases is OK.
The bad case is if PicoScope is stopped, so it is just showing the last trace, but not actively taking traces. It could be stopped because I hit stop (or space bar), or because it found an alarm condition. In this case, when the computer goes to sleep, PicoScope waits a few seconds and wakes it again, and acts as if you hit START! That is better than the hang, but what if I have a trace I haven't saved yet? I would not expect it to start the trace again if it was stopped before.
If the trace is stopped, shouldn't it just let the computer go to sleep? I haven't tried the Beta version on my laptop yet, but I commonly let it go to sleep so that the battery lasts longer, so I would normally stop the trace before leaving the computer for a long period.