SNMP problem

[cabildocl]

I have estimated the following problem.

1382:20111023:124152.973 SNMP Host [SW_SE_INTERIOR]: first network error, wait for 15 seconds
1387:20111023:124213.218 SNMP Host [SW_SE_INTERIOR]: another network error, wait for 15 seconds
1387:20111023:124228.267 Enabling SNMP host [Camaras_SF]
1387:20111023:124246.319 Enabling SNMP host [sw_capa3_electricos]
1385:20111023:124246.663 SNMP Host [Camaras_SF]: first network error, wait for 15 seconds
1387:20111023:124307.407 SNMP Host [Camaras_SF]: another network error, wait for 15 seconds
1385:20111023:124325.731 SNMP Host [sw_capa3_electricos]: first network error, wait for 15 seconds
1387:20111023:124346.543 SNMP Host [sw_capa3_electricos]: another network error, wait for 15 seconds
1387:20111023:124407.611 SNMP Host [sw_capa3_electricos]: another network error, wait for 15 seconds
1387:20111023:124428.672 Disabling SNMP host [sw_capa3_electricos]


and I have only 4 teams all configured via SNMP.

3 switch with 50 OID and a sensor with a 5.

Test different versions of zabbix, 1.8.7, 1.8.8 and 1.8.9, with the same results.

Please help