Error secLDAP

I am developing one application in Visual Studio Net 2003 with Business Objects XI (11.0.3300.0 dlls)

When I run my application, I am getting error at

enterpriseSession = sessionMgr.Logon("

The error is

System.Runtime.InteropServices.COMException: An internal error has occurred in the secLdap plugin.

I am using

My username, password, CMC and LDAP authentication type.

I really appreciate any help on this.