In midas.c, the bk_delete function removes a bank by decrementing the total
event size and then copying the remaining banks into the location of the first
using memcpy from string.h.

memcpy is not specified to handle overlapping memory regions (such as MIDAS
banks), though it seems most common implementations do.

memmove should be used instead, which is specified to behave as if copying
through an intermediate buffer.

I noticed the misbehavior using glibc with gcc version 4.4.4 and scientific
linux 6.0. Other gcc versions changed nothing, as this originates from the
implementation of memcpy in libc.

libc version:
GNU C Library stable release version 2.12, by Roland McGrath et al.
Compiled by GNU CC version 4.4.5 20110214 (Red Hat 4.4.5-6).
Compiled on a Linux 2.6.32 system on 2011-12-06.