Just found some little problem with 0.4.0-alpha:
scenerio: you're connected multiple times (diffrent nicknames) to the same network.
when you try to /keyx with a nick you already /keyx'ed with using a other of your connection, xchat chrashes.

gdb says:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb7148710 (LWP 28464)]
0xb735c613 in strlen () from /lib/tls/i686/cmov/libc.so.6
gdb backtrace:
#0 0xb735c613 in strlen () from /lib/tls/i686/cmov/libc.so.6
#1 0xb6d14132 in std::string::operator= () from /usr/lib/libstdc++.so.6
#2 0xb5901acf in mc_keyx () from /home/username/.xchat2/mircryption.so
#3 0x080a0ecc in ?? ()
#4 0x0809e76b in ?? ()
#5 0x0809f493 in ?? ()
#6 0x08071b36 in ?? ()
#7 0xb76d43a4 in g_cclosure_marshal_VOID__VOID () from /usr/lib/libgobject-2.0.so.0
#8 0xb76c6c7b in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#9 0xb76dce57 in ?? () from /usr/lib/libgobject-2.0.so.0
#10 0xb7c13670 in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#11 0xb7c13c2c in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#12 0xb7c13e9d in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#13 0xb7c1400e in gtk_bindings_activate_event () from /usr/lib/libgtk-x11-2.0.so.0
#14 0xb7c5fdef in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#15 0xb7cd9526 in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#16 0xb76c53d9 in ?? () from /usr/lib/libgobject-2.0.so.0
#17 0xb76c6ba8 in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#18 0xb76dcaff in ?? () from /usr/lib/libgobject-2.0.so.0
#19 0xb76de34f in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#20 0xb76de936 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#21 0xb7df42ae in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#22 0xb7e0811f in gtk_window_propagate_key_event () from /usr/lib/libgtk-x11-2.0.so.0
#23 0xb7e0b49c in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#24 0xb7cd9526 in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#25 0xb76c53d9 in ?? () from /usr/lib/libgobject-2.0.so.0
#26 0xb76c6c7b in g_closure_invoke () from /usr/lib/libgobject-2.0.so.0
#27 0xb76dcaff in ?? () from /usr/lib/libgobject-2.0.so.0
#28 0xb76de34f in g_signal_emit_valist () from /usr/lib/libgobject-2.0.so.0
#29 0xb76de936 in g_signal_emit () from /usr/lib/libgobject-2.0.so.0
#30 0xb7df42ae in ?? () from /usr/lib/libgtk-x11-2.0.so.0
#31 0xb7cd2041 in gtk_propagate_event () from /usr/lib/libgtk-x11-2.0.so.0
#32 0xb7cd3327 in gtk_main_do_event () from /usr/lib/libgtk-x11-2.0.so.0
#33 0xb7b6034a in ?? () from /usr/lib/libgdk-x11-2.0.so.0
#34 0xb749bb88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#35 0xb749f0eb in ?? () from /usr/lib/libglib-2.0.so.0
#36 0xb749f5ba in g_main_loop_run () from /usr/lib/libglib-2.0.so.0
#37 0xb7cd37d9 in gtk_main () from /usr/lib/libgtk-x11-2.0.so.0
#38 0x0806158b in ?? ()
#39 0x080aeebd in ?? ()
#40 0xb72fb775 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
#41 0x08055c31 in ?? ()
PS: os: ubuntu jaunty 32bit (all updates, Linux 2.6.28-11-generic) with xchat 2.8.6 (from the ubuntu jaunty backports).