Hi to all!

Some time ago I have a strange problem with memory alocation (while using stl containers). I attached c++ source files (ok.cpp and fail.cpp). In ok.cpp everything work "almost" fine, I mean almost all the memory is released after deleting all the elements. BUT the number of 500*8 elements on the list seems to be a limit somehow. In fail.cpp, the number of elements on the list is 500*16 (the size of single element is decreased to 1024*64 from 1024*128). Here, after deleting all the elements of the list and going out of the scope where the list is declared, there is no memory released.
1 How is that possible?
2 What to do? How to fix it?
Thanks for ANY help.