SSH Check failures with too many items

[JD2000]

I need to monitor the output of specific commands on remote machines. I setup SSH Check on one server and it works as intended, but once I apply these items to more servers, they start to fail.

12 instances of an SSH Check every 60 seconds seems to be the limit. If I decrease the time, or increase the instances, they randomly die and are marked as "Not Supported".

The log file shows

[SRV1:ssh.run[dicom]] became not supported: Public key authentication failed: Would block

I'm on 2.0.8. Built from source on a dedicated server.

[JD2000]

here is the log file in debug mode, showing one failure then one success. Any suggestions on how to troubleshoot this would be appreciated:

1500:20130903:091110.238 ssh_run() supported authentication methods:'publickey,gssapi-with-mic,password'
1496:20130903:091110.240 End of ssh_run():NOTSUPPORTED
1496:20130903:091110.240 Item [HUB1:ssh.run[utils]] error: Public key authentication failed: Would block
1496:20130903:091110.240 End of get_value():NOTSUPPORTED
1496:20130903:091110.240 In activate_host() hostid:10093 itemid:23827 type:13
1496:20130903:091110.240 End of get_values():1
1496:20130903:091110.240 poller #1 spent 3.000978 seconds while updating 1 values
1496:20130903:091110.240 In DCconfig_get_poller_nextcheck() poller_type:0
1496:20130903:091110.240 End of DCconfig_get_poller_nextcheck():1378213871
1496:20130903:091110.240 sleeping for 1 seconds
1500:20130903:091110.294 ssh_run() authentication by public key succeeded
1500:20130903:091110.350 ssh_run() exitcode: 0 bytecount: 3
1500:20130903:091110.351 End of ssh_run():SUCCEED
1500:20130903:091110.351 End of get_value():SUCCEED