I have the same problem with deluge svn version and libtorrent 0.15:

gdb --args python /usr/local/bin/deluged -d
GNU gdb (GDB) 7.0-ubuntu
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Leyendo símbolos desde /usr/bin/python...(no debugging symbols found)...hecho.
(gdb) run
Starting program: /usr/bin/python /usr/local/bin/deluged -d
[Thread debugging using libthread_db enabled]
[Nuevo Thread 0xb6fb3b70 (LWP 11848)]
[Nuevo Thread 0xb67b2b70 (LWP 11849)]
[Nuevo Thread 0xb5fb1b70 (LWP 11850)]
[Nuevo Thread 0xb55ffb70 (LWP 11851)]
[Thread 0xb55ffb70 (LWP 11851) terminado]
[ERROR   ] 20:01:33 init:50 Unable to enable plugin!
[ERROR   ] 20:01:33 init:51 'Core' object has no attribute '_timer'
Traceback (most recent call last):
  File "/usr/local/lib/python2.6/dist-packages/deluge-1.2.1-py2.6.egg/deluge/plugins/init.py", line 48, in enable
    self.plugin.enable()
  File "build/bdist.linux-i686/egg/freespace/core.py", line 76, in enable
    if not self._timer:
AttributeError: 'Core' object has no attribute '_timer'
python: malloc.c:3929: __libc_valloc: Afirmación `!p || ((((mchunkptr)((char*)(p) - 2*(sizeof(size_t)))))->size & 0x2) || ar_ptr == (((((mchunkptr)((char*)(p) - 2*(sizeof(size_t)))))->size & 0x4) ? ((heap_info *)((unsigned long)(((mchunkptr)((char*)(p) - 2*(sizeof(size_t))))) & ~((2 * (512 * 1024))-1)))->ar_ptr : &main_arena)' fallida.

Program received signal SIGABRT, Aborted.
[Cambiando a Thread 0xb67b2b70 (LWP 11849)]
0xffffe430 in __kernel_vsyscall ()
(gdb) bt
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb7e564d1 in raise () from /lib/tls/i686/cmov/libc.so.6
#2  0xb7e59932 in abort () from /lib/tls/i686/cmov/libc.so.6
#3  0xb7e4f648 in __assert_fail () from /lib/tls/i686/cmov/libc.so.6
#4  0xb7e9b6ef in valloc () from /lib/tls/i686/cmov/libc.so.6
#5  0xb72f66dd in libtorrent::page_aligned_allocator::malloc (bytes=262152) at allocator.cpp:78
#6  0xb7322c7a in boost::pool<libtorrent::page_aligned_allocator>::ordered_malloc_need_resize (this=0x84deb2c) at /usr/include/boost/pool/pool.hpp:461
#7  0xb7318b86 in boost::pool<libtorrent::page_aligned_allocator>::ordered_malloc (this=0x84de9a8, category=0xb74d3d1a "receive buffer")
    at /usr/include/boost/pool/pool.hpp:232
#8  libtorrent::disk_buffer_pool::allocate_buffer (this=0x84de9a8, category=0xb74d3d1a "receive buffer") at disk_io_thread.cpp:120
#9  0xb73d88f9 in libtorrent::aux::session_impl::allocate_disk_buffer (this=0x84de830, category=0xb74d3d1a "receive buffer") at session_impl.cpp:3399
#10 0xb73ab68a in libtorrent::peer_connection::allocate_disk_receive_buffer (this=0xb4be0c08, disk_buffer_size=16384) at peer_connection.cpp:3306
#11 0xb730566d in libtorrent::bt_peer_connection::on_piece (this=0xb4be0c08, received=1) at bt_peer_connection.cpp:1131
#12 0xb7301058 in libtorrent::bt_peer_connection::dispatch_message (this=0xb4be0c08, received=1) at bt_peer_connection.cpp:1600
#13 0xb7306368 in libtorrent::bt_peer_connection::on_receive (this=0xb4be0c08, error=..., bytes_transferred=1) at bt_peer_connection.cpp:2964
#14 0xb73b30e3 in libtorrent::peer_connection::on_receive_data (this=0xb4be0c08, error=..., bytes_transferred=5) at peer_connection.cpp:4356
#15 0xb73b7838 in call<boost::intrusive_ptr<libtorrent::peer_connection> const, boost::system::error_code const, unsigned int> (base=0xb4be10c0)
    at /usr/include/boost/bind/mem_fn_template.hpp:265
#16 operator()<boost::intrusive_ptr<libtorrent::peer_connection> > (base=0xb4be10c0) at /usr/include/boost/bind/mem_fn_template.hpp:286
#17 operator()<boost::_mfi::mf2<void, libtorrent::peer_connection, const boost::system::error_code&, unsigned int>, boost::_bi::list2<const boost::system::error_code&, const unsigned int&> > (base=0xb4be10c0) at /usr/include/boost/bind/bind.hpp:390
#18 operator()<boost::system::error_code, unsigned int> (base=0xb4be10c0) at /usr/include/boost/bind/bind_template.hpp:108
#19 operator()<boost::system::error_code, unsigned int> (base=0xb4be10c0) at ../include/libtorrent/peer_connection.hpp:1050
#20 boost::asio::detail::binder2<libtorrent::peer_connection::allocating_handler<boost::_bi::bind_t<void, boost::_mfi::mf2<void, libtorrent::peer_connection, boost::system::error_code const&, unsigned int>, boost::_bi::list3<boost::_bi::value<boost::intrusive_ptr<libtorrent::peer_connection> >, boost::arg<1>, boost::arg<2> > >, 256u>, boost::system::error_code, unsigned int>::operator() (base=0xb4be10c0) at /usr/include/boost/asio/detail/bind_handler.hpp:96
#21 asio_handler_invoke<boost::asio::detail::binder2<libtorrent::peer_connection::allocating_handler<boost::_bi::bind_t<void, boost::_mfi::mf2<void, libtorrent---Type <return> to continue, or q <return> to quit---
::peer_connection, boost::system::error_code const&, unsigned int>, boost::_bi::list3<boost::_bi::value<boost::intrusive_ptr<libtorrent::peer_connection> >, boost::arg<1>, boost::arg<2> > >, 256u>, boost::system::error_code, unsigned int> > (base=0xb4be10c0) at /usr/include/boost/asio/handler_invoke_hook.hpp:62
#22 invoke<boost::asio::detail::binder2<libtorrent::peer_connection::allocating_handler<boost::_bi::bind_t<void, boost::_mfi::mf2<void, libtorrent::peer_connection, boost::system::error_code const&, unsigned int>, boost::_bi::list3<boost::_bi::value<boost::intrusive_ptr<libtorrent::peer_connection> >, boost::arg<1>, boost::arg<2> > >, 256u>, boost::system::error_code, unsigned int>, libtorrent::peer_connection::allocating_handler<boost::_bi::bind_t<void, boost::_mfi::mf2<void, libtorrent::peer_connection, boost::system::error_code const&, unsigned int>, boost::_bi::list3<boost::_bi::value<boost::intrusive_ptr<libtorrent::peer_connection> >, boost::arg<1>, boost::arg<2> > >, 256u> > (base=0xb4be10c0) at /usr/include/boost/asio/detail/handler_invoke_helpers.hpp:39
#23 asio_handler_invoke<boost::asio::detail::binder2<libtorrent::peer_connection::allocating_handler<boost::_bi::bind_t<void, boost::_mfi::mf2<void, libtorrent::peer_connection, boost::system::error_code const&, unsigned int>, boost::_bi::list3<boost::_bi::value<boost::intrusive_ptr<libtorrent::peer_connection> >, boost::arg<1>, boost::arg<2> > >, 256u>, boost::system::error_code, unsigned int>, libtorrent::peer_connection::allocating_handler<boost::_bi::bind_t<void, boost::_mfi::mf2<void, libtorrent::peer_connection, boost::system::error_code const&, unsigned int>, boost::_bi::list3<boost::_bi::value<boost::intrusive_ptr<libtorrent::peer_connection> >, boost::arg<1>, boost::arg<2> > >, 256u>, boost::system::error_code, unsigned int> (base=0xb4be10c0)
    at /usr/include/boost/asio/detail/bind_handler.hpp:130
#24 invoke<boost::asio::detail::binder2<libtorrent::peer_connection::allocating_handler<boost::_bi::bind_t<void, boost::_mfi::mf2<void, libtorrent::peer_connection, boost::system::error_code const&, unsigned int>, boost::_bi::list3<boost::_bi::value<boost::intrusive_ptr<libtorrent::peer_connection> >, boost::arg<1>, boost::arg<2> > >, 256u>, boost::system::error_code, unsigned int>, boost::asio::detail::binder2<libtorrent::peer_connection::allocating_handler<boost::_bi::bind_t<void, boost::_mfi::mf2<void, libtorrent::peer_connection, boost::system::error_code const&, unsigned int>, boost::_bi::list3<boost::_bi::value<boost::intrusive_ptr<libtorrent::peer_connection> >, boost::arg<1>, boost::arg<2> > >, 256u>, boost::system::error_code, unsigned int> > (base=0xb4be10c0)
    at /usr/include/boost/asio/detail/handler_invoke_helpers.hpp:39
#25 boost::asio::detail::handler_queue::handler_wrapper<boost::asio::detail::binder2<libtorrent::peer_connection::allocating_handler<boost::_bi::bind_t<void, boost::_mfi::mf2<void, libtorrent::peer_connection, boost::system::error_code const&, unsigned int>, boost::_bi::list3<boost::_bi::value<boost::intrusive_ptr<libtorrent::peer_connection> >, boost::arg<1>, boost::arg<2> > >, 256u>, boost::system::error_code, unsigned int> >::do_call (base=0xb4be10c0)
    at /usr/include/boost/asio/detail/handler_queue.hpp:192
#26 0xb735ffb1 in boost::asio::detail::task_io_service<boost::asio::detail::epoll_reactor<false> >::run(boost::system::error_code&) ()
   from /usr/local/lib/libtorrent-rasterbar.so.6
#27 0xb73eccfc in boost::asio::io_service::run (this=0x84de830) at /usr/include/boost/asio/impl/io_service.ipp:65
#28 libtorrent::aux::session_impl::operator() (this=0x84de830) at session_impl.cpp:2495
---Type <return> to continue, or q <return> to quit---
#29 0xb73fbfa3 in boost::detail::thread_data<boost::reference_wrapper<libtorrent::aux::session_impl> >::run() () from /usr/local/lib/libtorrent-rasterbar.so.6
#30 0xb71daab5 in thread_proxy () from /usr/lib/libboost_thread.so.1.40.0
#31 0xb7fbb80e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#32 0xb7ef88de in clone () from /lib/tls/i686/cmov/libc.so.6
----------------------------------------------------

Is there any solution or workaround?