Blendcache files not working on other systems

Hello. I have found a problem in Blender 2.59 where I bake a cloth sim on a PC, save and close the file, open the .blend file on a Mac, and when I play the simulation (Alt+A), it doesn’t run. It appears as though Blender can see the blendcache files – Blender reports X amount of files on disk and the blue strip that indicates a cached simulation is even in the timeline – but for some reason the simulation doesn’t work. The opposite is also true: I can bake the simulation on a Mac, and then the simulation doesn’t work on a PC. However, when I open the .blend file on another Mac, it works just fine.

Can anyone explain why blendcache files written by a Mac can’t be used by a PC and vice-versa?