devide will reboot shortly

Why does our hardware firewall sometimes reboot?

this is the log just before the rebooting (this IP 85.18.xxx.xxx is my IP):

2007-12-11 14:09:42 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 207.46.106.77 port 1863 to 85.18.xxx.xxx port 35051 TCP ACK (default) @2007-12-11-14:12:48 2007-12-11 14:09:42 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 207.46.106.55 port 1863 to 85.18.xxx.xxx port 35076 TCP ACK FIN PSH (default) @2007-12-11-14:12:48 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 207.46.106.28 port 1863 to 85.18.xxx.xxx port 35267 TCP ACK (default) @2007-12-11-14:12:48 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 207.46.106.60 port 1863 to 85.18.xxx.xxx port 35239 TCP ACK (default) @2007-12-11-14:12:48 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 192.168.14.117 port 3165 to 1.93.7.218 port 3193 TCP ACK FIN (Attempt to send TCP packet on an unopen port) @2007-12-11-14:12:48 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 212.247.9.195 port 443 to 85.18.xxx.xxx port 35162 TCP ACK PSH (default) @2007-12-11-14:12:48 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 212.247.9.195 port 443 to 85.18.xxx.xxx port 35286 TCP ACK PSH (default) @2007-12-11-14:12:48 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 212.247.9.195 port 443 to 85.18.xxx.xxx port 33314 TCP ACK PSH (default) @2007-12-11-14:12:48 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 151.68.198.237 port 31209 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:48 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 82.49.188.196 port 12846 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 216.155.193.169 port 5050 to 85.18.xxx.xxx port 31809 TCP ACK FIN PSH (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 86.20.201.125 port 48057 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 81.75.222.210 port 50295 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 151.56.141.188 port 46262 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 87.13.26.177 port 6143 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Info 192.168.14.1 706703571CBAB IP: ICMP type (3) code (3) received from 158.195.151.146 @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 85.27.65.45 port 55450 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 86.12.254.248 port 39196 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 213.39.226.184 to 85.18.xxx.xxx ICMP type (3) code (3) (SIP discarded) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 151.68.44.10 port 36639 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 82.58.157.86 port 5443 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 81.83.181.103 port 32845 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 82.84.111.204 to 85.18.xxx.xxx ICMP type (3) code (3)(SIP discarded) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 85.201.5.70 to 85.18.xxx.xxx ICMP type (3) code (3)(SIP discarded) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 91.171.152.138 port 11847 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 88.178.249.86 port 41026 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 85.231.106.180 port 20192 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:43 Local0.Warning 192.168.14.1 706703571CBAB IP: discard from 88.107.56.98 port 64693 to 85.18.xxx.xxx port 38129 UDP (default) @2007-12-11-14:12:49 2007-12-11 14:09:48 Local0.Error 192.168.14.1 706703571CBAB MONITOR: critical task tNetTask suspended - device will reboot shortly @2007-12-11-14:12:53 2007-12-11 14:09:48 Local0.Error 192.168.14.1 706703571CBAB MONITOR: @2007-12-11-14:12:53

any idea?