Service account login issue

Hello All,

We have a service account login issue in vCenter. Account gets locked frequently and we have to unlock each time. Not sure of the issue.

14-08-25T17:16:35.989-04:00 [04616 verbose 'Default' opID=b765de9b] [VpxVmomi] Invoke error: vim.SessionManager.login session: 5204aa89-f750-8298-1310-5f8dadc2543b Throw: vim.fault.InvalidLogin

2014-08-25T17:16:35.989-04:00 [04616 verbose 'SoapAdapter.HTTPService' opID=b765de9b] User agent is 'Mozilla/4.0 (compatible; MSIE 6.0; MS Web Services Client Protocol 2.0.50727.3655)'

2014-08-25T17:16:35.989-04:00 [04616 verbose 'SoapAdapter.HTTPService' opID=b765de9b] HTTP Response: Complete (processed 584 bytes)

2014-08-25T17:16:35.989-04:00 [04616 info 'Default' opID=b765de9b] [VpxLRO] -- FINISH task-internal-3518975 --  -- vim.SessionManager.login -- 5204aa89-f750-8298-1310-5f8dadc2543b

2014-08-25T17:16:35.989-04:00 [04616 info 'Default' opID=b765de9b] [VpxLRO] -- ERROR task-internal-3518975 --  -- vim.SessionManager.login: vim.fault.InvalidLogin:

--> Result:

--> (vim.fault.InvalidLogin) {

-->    dynamicType = <unset>,

-->    faultCause = (vmodl.MethodFault) null,

-->    msg = "",

--> }

--> Args:

-->

--> Arg userName:

--> "r1-core\xxxxxx"

--> Arg password:

--> (not shown)

-->

--> Arg locale:

These are some logs with error messages. Please have a look and see if someone can help me with this.

Thank you,

vamsi.