Modem shutdown and reboots periodically in Arizona

Problem： Modem restarts every 40 minutes or so, losing internet connection periodically. This is a SB5101 modem. Any potential fixes?

Signal
Downstream
Frequency 849000000 Hz
Signal To Noise Ratio 36.4 dB
Power Level -9.5 dBmV

Upstream
Channel ID 2
Frequency 29600000 Hz
Power 45.7 dBmV

Log:

2014-03-19 22:43:37	6-Notice	M573.0	Modem Is Shutting Down and Rebooting...
2014-03-19 22:43:37	3-Critical	R004.0	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance o
2014-03-19 22:43:04	3-Critical	R005.0	Started Unicast Maintenance Ranging - No Response received - T3 time-out
2014-03-19 22:42:50	4-Error	C401.0	DCC-ACK not received
2014-03-19 22:42:50	3-Critical	R005.0	Started Unicast Maintenance Ranging - No Response received - T3 time-out
2014-03-19 22:42:50	4-Error	C401.0	DCC-ACK not received
2014-03-19 22:42:49	3-Critical	R005.0	Started Unicast Maintenance Ranging - No Response received - T3 time-out
2014-03-19 22:42:49	4-Error	C401.0	DCC-ACK not received
1970-01-01 00:01:25	6-Notice	I401.0	TLV-11 - unrecognized OID
1970-01-01 00:01:25	5-Warning	D004.1	ToD request sent - No Response received
1970-01-01 00:01:18	5-Warning	D003.0	DHCP WARNING - Non-critical field invalid in response ;CM-MAC=00:17:ee:60:a7:30;
1970-01-01 00:01:15	3-Critical	D001.0	DHCP FAILED - Discover sent, no offer received;CM-MAC=00:17:ee:60:a7:30;CMTS-MAC
1970-01-01 00:00:09	6-Notice	M571.1	Ethernet link up - ready to pass packets
2014-03-19 21:03:12	6-Notice	M573.0	Modem Is Shutting Down and Rebooting...