AFAIK stack and heap is not associated to any objects. The stack memory is allocated while we creates a thread. The default stack and heap size is 1 MB. You can specify the stack size while creating a thread/fork. If you are building an EXE, you can set the size of stack in linker options using /STACK option. you can specify the heap size using /HEAP:reserve[,commit]
Re: question: what is the stack size in MFC objects
I am going to mark this thread as answered since you have not followed up with any further information on your problem as requested for over a week - I assume you solved the problem yourself or one of the suggestions in this thread helped you solved the problem. If you have a solution you could post it so others can find it. If you do not have a solution then please submit further details and then mark the thread as unanswered.
PS: In hindsight however, the more appropriate place for your question was probably the MFC newsgroup: http://msdn.microsoft.com/newsgroups/default.aspx dg=microsoft.public.vc.mfc&lang=en&cr=US