The object heap layout code should enforce that the lower boundary of the heap is 64K aligned, and that all space sizes are 64K aligned as well, otherwise the space table lookup could give invalid results. Also, max heap size should be 2MB aligned since the card marking array is committed in 4K page sizes (4K * 512 bytes = 2MB) (all sizes related to current win32 constants).

This is a potential problem - does not seem to occur in practice on win32 and solaris.