[Users] out of memory

Hello, Lately our OpenSER 1.1.1 is running out of memory and I get the following message 4(25190) get_hdr_field: out of memory The result is that it stops processing any incoming request. This is a production system and of course it causes a great deal of frustration. The last time this happened I got the following statistics before restarting Total statistics = 37 Total modules = 5 Module name = core; statistics=8 core:rcv_requests = 3259334 core:rcv_replies = 8816 core:fwd_requests = 736 core:fwd_replies = 137 core:drop_requests = 743 core:drop_replies = 0 core:err_requests = 0 core:err_replies = 43 Module name = shmem; statistics=6 shmem:total_size = 268435456 shmem:used_size = 1675864 shmem:real_used_size = 1835104 shmem:max_used_size = 4399048 shmem:free_size = 266600352 shmem:fragments = 17710 Module name = sl; statistics=9 sl:1xx_replies = 0 sl:2xx_replies = 1690410 sl:3xx_replies = 43 sl:4xx_replies = 334827 sl:5xx_replies = 1185629 sl:6xx_replies = 0 sl:sent_replies = 3210909 sl:sent_err_replies = 0 sl:received_ACKs = 743 Module name = tm; statistics=11 tm:received_replies = 8636 tm:relayed_replies = 7096 tm:local_replies = 1718 tm:UAS_transactions = 7003 tm:UAC_transactions = 94 tm:2xx_transactions = 1528 tm:3xx_transactions = 3 tm:4xx_transactions = 5129 tm:5xx_transactions = 468 tm:6xx_transactions = 0 tm:inuse_transactions = 0 Module name = usrloc; statistics=3 usrloc:location-users = 0 usrloc:location-contacts = 0 usrloc:location-expires = 7282 I am not sure how to read these numbers but I see a big "free_size" and still OpenSER is out of memory. Any suggestions? thank you George Disclaimer The information in this e-mail and any attachments is confidential. It is intended solely for the attention and use of the named addressee(s). If you are not the intended recipient, or person responsible for delivering this information to the intended recipient, please notify the sender immediately. Unless you are the intended recipient or his/her representative you are not authorized to, and must not, read, copy, distribute, use or retain this message or any part of it. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses.