Comment 2 for bug 796891

StacktraceTop:
 __kernel_vsyscall ()
 raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
 abort () at abort.c:92
 ped_assert (cond_text=0xedf2aa "offset >= 0", file=0xedf274 "../../libparted/cs/geom.c", line=296, function=0xedf400 "ped_geometry_read") at ../../libparted/debug.c:112
 ped_geometry_read (geom=0x93e94d0, buffer=0xbff3575c, offset=-1, count=1) at ../../libparted/cs/geom.c:296