probleme unpack table compréssé

Bonjour
souci sur un unpack de table myisam


root@p1ak13 test2]# myisamchk --unpack tb_compres.MYI


*** glibc detected *** myisamchk: double free or corruption (out): 0x00000000071fe280 ***
======= Backtrace: =========
/lib64/libc.so.6[0x33b06714af]
/lib64/libc.so.6(cfree+0x4b)[0x33b06757ab]
myisamchk(mi_close+0x245)[0x427385]
myisamchk(recreate_table+0x3e9)[0x42dbb5]
myisamchk[0x410046]
myisamchk(main+0x1c8)[0x411d99]
/lib64/libc.so.6(__libc_start_main+0xf4)[0x33b061d9f4]
myisamchk[0x40e779]
======= Memory map: ========
00400000-00550000 r-xp 00000000 08:01 467988 /usr/bin/myisamchk
00750000-00789000 rw-p 00150000 08:01 467988 /usr/bin/myisamchk
00789000-00794000 rw-p 00789000 00:00 0
00988000-0098d000 rw-p 00188000 08:01 467988 /usr/bin/myisamchk
071fd000-0721e000 rw-p 071fd000 00:00 0 [heap]
33b0200000-33b021c000 r-xp 00000000 08:01 819264 /lib64/ld-2.5.so
33b041c000-33b041d000 r--p 0001c000 08:01 819264 /lib64/ld-2.5.so
33b041d000-33b041e000 rw-p 0001d000 08:01 819264 /lib64/ld-2.5.so
33b0600000-33b074f000 r-xp 00000000 08:01 819743 /lib64/libc-2.5.so
33b074f000-33b094f000 ---p 0014f000 08:01 819743 /lib64/libc-2.5.so
33b094f000-33b0953000 r--p 0014f000 08:01 819743 /lib64/libc-2.5.so
33b0953000-33b0954000 rw-p 00153000 08:01 819743 /lib64/libc-2.5.so
33b0954000-33b0959000 rw-p 33b0954000 00:00 0
33b0e00000-33b0e16000 r-xp 00000000 08:01 819746 /lib64/libpthread-2.5.so
33b0e16000-33b1016000 ---p 00016000 08:01 819746 /lib64/libpthread-2.5.so
33b1016000-33b1017000 r--p 00016000 08:01 819746 /lib64/libpthread-2.5.so
33b1017000-33b1018000 rw-p 00017000 08:01 819746 /lib64/libpthread-2.5.so
33b1018000-33b101c000 rw-p 33b1018000 00:00 0
33b1200000-33b1214000 r-xp 00000000 08:01 819761 /lib64/libz.so.1.2.3
33b1214000-33b1413000 ---p 00014000 08:01 819761 /lib64/libz.so.1.2.3
33b1413000-33b1414000 rw-p 00013000 08:01 819761 /lib64/libz.so.1.2.3
33b1600000-33b1682000 r-xp 00000000 08:01 819744 /lib64/libm-2.5.so
33b1682000-33b1881000 ---p 00082000 08:01 819744 /lib64/libm-2.5.so
33b1881000-33b1882000 r--p 00081000 08:01 819744 /lib64/libm-2.5.so
33b1882000-33b1883000 rw-p 00082000 08:01 819744 /lib64/libm-2.5.so
33b2600000-33b2615000 r-xp 00000000 08:01 819748 /lib64/libnsl-2.5.so
33b2615000-33b2814000 ---p 00015000 08:01 819748 /lib64/libnsl-2.5.so
33b2814000-33b2815000 r--p 00014000 08:01 819748 /lib64/libnsl-2.5.so
33b2815000-33b2816000 rw-p 00015000 08:01 819748 /lib64/libnsl-2.5.so
33b2816000-33b2818000 rw-p 33b2816000 00:00 0
33b2a00000-33b2a09000 r-xp 00000000 08:01 819757 /lib64/libcrypt-2.5.so
33b2a09000-33b2c08000 ---p 00009000 08:01 819757 /lib64/libcrypt-2.5.so
33b2c08000-33b2c09000 r--p 00008000 08:01 819757 /lib64/libcrypt-2.5.so
33b2c09000-33b2c0a000 rw-p 00009000 08:01 819757 /lib64/libcrypt-2.5.so
33b2c0a000-33b2c38000 rw-p 33b2c0a000 00:00 0
3995e00000-3995e0d000 r-xp 00000000 08:01 819243 /lib64/libgcc_s-4.1.2-20080825.so.1
3995e0d000-399600d000 ---p 0000d000 08:01 819243 /lib64/libgcc_s-4.1.2-20080825.so.1
399600d000-399600e000 rw-p 0000d000 08:01 819243 /lib64/libgcc_s-4.1.2-20080825.so.1
2b7d021a8000-2b7d021aa000 rw-p 2b7d021a8000 00:00 0
2b7d021b4000-2b7d021b7000 rw-p 2b7d021b4000 00:00 0
2b7d021b7000-2b7d021b8000 ---p 2b7d021b7000 00:00 0
2b7d021b8000-2b7d02bb8000 rw-p 2b7d021b8000 00:00 0
7fffbe30a000-7fffbe31f000 rw-p 7ffffffe9000 00:00 0 [stack]
7fffbe3fd000-7fffbe400000 r-xp 7fffbe3fd000 00:00 0 [vdso]
ffffffffff600000-ffffffffffe00000 ---p 00000000 00:00 0 [vsyscall]


verison de mysql 5.1.61

le user mysql n est pas activé >> nologin dans /etc/password

merci