Debuging out of memory while using shm

[Oliver Schulze L.]

Hi,
I have
IMP 2.2.6
Horde 1.2.6

and I'm using shared memory for the session storage.

Sometimes imp stop working and show only this message:

Warning: variable key 1 doesn't exist in /var/www/phplib/ct_shm.inc on 
line 79

I'm trying to identify why this happend.
If I:
stop apache
delete the shm segment
start apache

All start working again.

Could it be that IMP get out of memory when sending a big attachment?
I have a:
upload_max_filesize=20M
in php.ini and my shm segment looks like this:
class HordeCT extends CT_Shm {
  var $max_sessions   = 700;               // number of maximum sessions
  var $shm_key        = 0x123754;          // unique shm identifier
  var $shm_size       = 8000000;             // size of segment
}

Thanks
Oliver

-- 
Oliver Schulze L.
oliver@samera.com.py
Asuncion-Paraguay