game segfaults on exit

[Milo]

Program received signal SIGSEGV, Segmentation fault.
0x0000000000000661 in ?? ()
(gdb) bt
#0 0x0000000000000661 in ?? ()
#1 0x0000000000410d39 in boost::checked_delete<Player> (x=0xfd3f90)
    at /usr/include/boost/checked_delete.hpp:34
#2 0x000000000041132d in boost::detail::sp_counted_impl_p<Player>::dispose (
    this=0xfd3410) at /usr/include/boost/smart_ptr/detail/sp_counted_impl.hpp:78
#3 0x00000000004091d0 in boost::detail::sp_counted_base::release (this=0xfd3410)
    at /usr/include/boost/smart_ptr/detail/sp_counted_base_gcc_x86.hpp:145
#4 0x0000000000409200 in ~shared_count (this=0xfd3208,
    __in_chrg=<value optimized out>)
    at /usr/include/boost/smart_ptr/detail/shared_count.hpp:217
#5 0x0000000000409eb3 in ~shared_ptr (this=0xfd3200,
    __in_chrg=<value optimized out>)
    at /usr/include/boost/smart_ptr/shared_ptr.hpp:160
#6 0x0000000000410ed0 in std::_Destroy<boost::shared_ptr<Player> > (
    __pointer=0xfd3200)
    at /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.4/include/g++-v4/bits/stl_construct.h:88
#7 0x0000000000410eed in std::_Destroy<boost::shared_ptr<Player>*> (
    __first=0xfd3200, __last=0xfd3240)
    at /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.4/include/g++-v4/bits/stl_construct.h:103
#8 0x0000000000410f1f in std::_Destroy<boost::shared_ptr<Player>*, boost::shared_ptr<Player> > (__first=0xfd3200, __last=0xfd3240)
    at /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.4/include/g++-v4/bits/stl_construct.h:128
#9 0x0000000000411d65 in ~vector (this=0x7fffffffd9d8,
    __in_chrg=<value optimized out>)
    at /usr/lib/gcc/x86_64-pc-linux-gnu/4.3.4/include/g++-v4/bits/stl_vector.h:300
#10 0x0000000000410208 in ~Engine (this=0x7fffffffbd70,
    __in_chrg=<value optimized out>) at Engine.cpp:28
#11 0x0000000000413618 in main (argc=1, argv=0x7fffffffdb48) at Launch.cpp:33

Apparently something tries to delete a shared_ptr while it isn't necessary.