double free or corruption in siege

Running siege with default config on i686:

perbu@pad:~$ siege http://localhost/ &> foo
*** glibc detected *** siege: double free or corruption (out): 0x0805c1e8 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0xb7c978bd]
/lib/tls/i686/cmov/libc.so.6(__libc_free+0x84)[0xb7c97a44]
siege[0x80549bd]
siege[0x805421f]
siege[0x8054388]
siege[0x8051489]
/lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xdc)[0xb7c468cc]
siege[0x804a461]
======= Memory map: ========
08048000-08058000 r-xp 00000000 08:02 855192 /usr/bin/siege
08058000-08059000 rw-p 0000f000 08:02 855192 /usr/bin/siege
08059000-0807d000 rw-p 08059000 00:00 0 [heap]
b0300000-b0321000 rw-p b0300000 00:00 0
b0321000-b0400000 ---p b0321000 00:00 0
b0402000-b040c000 r-xp 00000000 08:02 66557 /lib/libgcc_s.so.1
b040d000-b040e000 ---p b040d000 00:00 0
b040e000-b0c0e000 rw-p b040e000 00:00 0
b0c0e000-b0c0f000 ---p b0c0e000 00:00 0
b0c0f000-b140f000 rw-p b0c0f000 00:00 0
b140f000-b1410000 ---p b140f000 00:00 0
b1410000-b1c10000 rw-p b1410000 00:00 0
b1c10000-b1c11000 ---p b1c10000 00:00 0
b1c11000-b2411000 rw-p b1c11000 00:00 0
b2411000-b2412000 ---p b2411000 00:00 0
b2412000-b2c12000 rw-p b2412000 00:00 0
b2c12000-b2c13000 ---p b2c12000 00:00 0
b2c13000-b3413000 rw-p b2c13000 00:00 0
b3413000-b3414000 ---p b3413000 00:00 0
b3414000-b3c14000 rw-p b3414000 00:00 0
b3c14000-b3c15000 ---p b3c14000 00:00 0
b3c15000-b4415000 rw-p b3c15000 00:00 0
b4415000-b4416000 ---p b4415000 00:00 0
b4416000-b4c16000 rw-p b4416000 00:00 0
b4c16000-b4c17000 ---p b4c16000 00:00 0
b4c17000-b5417000 rw-p b4c17000 00:00 0
b5417000-b5418000 ---p b5417000 00:00 0
b5418000-b5c18000 rw-p b5418000 00:00 0
b5c18000-b5c19000 ---p b5c18000 00:00 0
b5c19000-b6419000 rw-p b5c19000 00:00 0
b6419000-b641a000 ---p b6419000 00:00 0
b641a000-b6c1a000 rw-p b641a000 00:00 0
b6c1a000-b6c1b000 ---p b6c1a000 00:00 0
b6c1b000-b741b000 rw-p b6c1b000 00:00 0
b741b000-b741c000 ---p b741b000 00:00 0
b741c000-b7c1d000 rw-p b741c000 00:00 0
b7c1d000-b7c30000 r-xp 00000000 08:02 847893 /usr/lib/libz.so.1.2.3
b7c30000-b7c31000 rw-p 00012000 08:02 847893 /usr/lib/libz.so.1.2.3
b7c31000-b7d5e000 r-xp 00000000 08:02 65373 /lib/tls/i686/cmov/libc-2.4.so
b7d5e000-b7d60000 r--p 0012c000 08:02 65373 /lib/tls/i686/cmov/libc-2.4.so
b7d60000-b7d62000 rw-p 0012e000 08:02 65373 /lib/tls/i686/cmov/libc-2.4.so
b7d62000-b7d65000 rw-p b7d62000 00:00 0
b7d65000-b7e87000 r-xp 00000000 08:02 863878 /usr/lib/i686/cmov/libcrypto.so.0.9.8
b7e87000-b7e9c000 rw-p 00121000 08:02 863878 /usr/lib/i686/cmov/libcrypto.so.0.9.8
b7e9c000-b7e9f000 rw-p b7e9c000 00:00 0
b7e9f000-b7eda000 r-xp 00000000 08:02 863879 /usr/lib/i686/cmov/libssl.so.0.9.8
b7eda000-b7ede000 rw-p 0003b000 08:02 863879 /usr/lib/i686/cmov/libssl.so.0.9.8
b7ede000-b7edf000 rw-p b7ede000 00:00 0
b7edf000-b7ee1000 r-xp 00000000 08:02 65379 /lib/tls/i686/cmov/libdl-2.4.so
b7ee1000-b7ee3000 rw-p 00001000 08:02 65379 /lib/tls/i686/cmov/libdl-2.4.so
b7ee3000-b7ef2000 r-xp 00000000 08:02 65423 /lib/tls/i686/cmov/libpthread-2.4.so
b7ef2000-b7ef4000 rw-p 0000f000 08:02 65423 /lib/tls/i686/cmov/libpthread-2.4.so
b7ef4000-b7ef6000 rw-p b7ef4000 00:00 0
b7f04000-b7f06000 rw-p b7f04000 00:00 0
b7f06000-b7f1f000 r-xp 00000000 08:02 65349 /lib/ld-2.4.so
b7f1f000-b7f21000 rw-p 00018000 08:02 65349 /lib/ld-2.4.so
bffe8000-bfffe000 rw-p bffe8000 00:00 0 [stack]
ffffe000-fffff000 ---p 00000000 00:00 0 [vdso]
Aborted (core dumped)