Mainly because I'm (Ajarn) tired... and not too sure about these, or future ones even...
I'll report GDB's here. MouseJstr, this is mainly for you.

svn 770:
-----------------
#0  buildin_sc_start (st=0xbfbfea30) at script.c:4225
4225            if(bl->type == BL_PC && ((struct map_session_data *)bl)->state.potionpitcher_flag)
(gdb) print bl
$3 = (struct block_list *) 0x0
(gdb) where
#0  buildin_sc_start (st=0xbfbfea30) at script.c:4225
#1  0x08093f5d in run_func (st=0xbfbfea30) at script.c:6680
#2  0x08094171 in run_script_main (script=0xf54a000 "\b\002", pos=502, rid=2000181, oid=110001888,
    st=0xbfbfea30, rootscript=0x0) at script.c:6754
#3  0x08094301 in run_script (script=0xf54a000 "\b\002", pos=502, rid=2000181, oid=110001888) at script.c:6880
#4  0x08079115 in npc_scriptcont (sd=0x1c9d7000, id=110001888) at npc.c:923
#5  0x08064485 in clif_parse (fd=54) at clif.c:10352
#6  0x080e1629 in do_parsepacket () at socket.c:452
#7  0x080e0b11 in main (argc=1, argv=0xbfbfec88) at core.c:176
#8  0x080497e2 in _start ()

----

#0  0x080d8d80 in guild_member_leaved (guild_id=10030, account_id=2000740, char_id=151069, flag=0,
    name=0x1c567037 "kloyd", mes=0x1c56700f "?") at guild.c:685
685                                             sd2=guild_getavailablesd(g);
(gdb) print g
$5 = (struct guild *) 0x0
(gdb) where
#0  0x080d8d80 in guild_member_leaved (guild_id=10030, account_id=2000740, char_id=151069, flag=0,
    name=0x1c567037 "kloyd", mes=0x1c56700f "?") at guild.c:685
#1  0x080d53ab in intif_parse_GuildMemberLeaved (fd=0) at intif.c:918
#2  0x080d5acc in intif_parse (fd=9) at intif.c:1123
#3  0x080503a2 in chrif_parse (fd=9) at chrif.c:1004
#4  0x080e1629 in do_parsepacket () at socket.c:452
#5  0x080e0b11 in main (argc=1, argv=0xbfbfedf4) at core.c:176
#6  0x080497e2 in _start ()

-----------------

That's all I got for now. I'll keep adding them as they show up (if they are simple),
if you are away Mouse (or whoever wants to fix them). Reply to them as they are fixed.