Problem with data replication in Informix On-Line

HELP! Informix On-Line 7.23 on SCO UNIX Open Server 5.0.4 Both servers are identically configured. Data Replication starts fine but Secondary server allocates memory as quick as 16MB per hour: 14:31 dynamically allocated new shared memory segment (size 8388608) what makes him die in about 24 hours. You can't even log in. 16:34 shmat: [NOMEM][12]: out of avaiable data space, check system MAXMEM 16:34 out of virtual shared memory Primary database can't communicate with Secondary and blocks which makes whole system unusable. How to fix it? Thank you very much. Tomasz Szafranski