I use MiniMg V2 in Logic 9 and Snow Leopard without any problems on my MacBook Pro 2.4 Ghz, 4 Gb RAM.
Maybe it's something to do with how you've setup your system.
It's true that Arturia's plugins can be CPU intensive - the occasional preset can overload the CPU and turn into a blast of awful noise - but I can't recall them ever having crashed Logic.