Ah, stupid me, I added the housekeeping costs in the "allocate" part, but not in the "free" part. Sorry, I'll fix the code asap.
Rev 1311 is ready for your testing
I have a feeling that this issue is MSVC 2012's fault. Its STL probably uses a different allocation scheme for vectors - each vector created allocates something small off the heap. With MCServer using thousands of vectors simultaneously (16 per chunk for each fluid simulator), this allocation will very soon overwhelm the leakfinder.
Rev 1311 is ready for your testing

I have a feeling that this issue is MSVC 2012's fault. Its STL probably uses a different allocation scheme for vectors - each vector created allocates something small off the heap. With MCServer using thousands of vectors simultaneously (16 per chunk for each fluid simulator), this allocation will very soon overwhelm the leakfinder.