os x crash

After updating to 1.2.8 on OS X, Leopard, Intel chipset, Miro started causing system crashes (not kernel panics, just a freeze). It's very predictable in that it if runs for ~24 hours, it will always crash but if it only runs 6 hours or less (I haven't tested time in between) it never crashes. I'm going out on a limb to guess there's a memory leak that takes a number of hours to accumulate. I'll try running with a clean profile and confirm what the last working version was. What else can I do to help track down this bug?