I asked about an error that i found in my IB log file on an IB support
forum:

gds__free: attempt to release bad block

this error is registered about 10 times per second and the ib server turns
really slow.

On that forum, Claudio Valderrama told me that either the engine has
problems with its memory blocks and the internal
allocation routines or IBO is requesting it to free a block of memory whose
address is invalid (it's not in the list of allocated blocks).

So, i'd like to know when does IBO request to free a block of memmory on the
server? and why could this error be? (probably a not well formed query that
makes the server hang?)

Thanks