I've been getting frequent "not responding" crashes using MC 8.4.1 on a Mac Pro (trash can).

System  info:

Mac Pro

3.5 GHz 6-Core Intel Xeon E5

32GB 1866 MHz DDR3

OSX: 10.9.5

Graphics: AMD FirePro D700 (EFI Driver: 01.00.687)

It seems to hang when I'm undoing a command but I haven't kept a log of when the issue occurs. I'll start doing that. 

Vague info to go on but has anyone else experienced this issue with a similar setup? 

It has been an issue I've just been putting with but if there's a solution than all the better!

Thanks for any help!