mpirringer got that one on the nose there. Though they have fixed most of the memory leaks in the newer version.
If I run the same print without reslicing I can run it forever without a problem.
Though after several slices I restart MC. If I don't the computer runs slow and older versions crash.
The thing is, MC (at least older versions) don't take advantage of anything over 8 gig of memory. The computer I run it on has 16, but MC never uses more than 6.9 gig. It just starts having issues after it uses up its allotted amount.