Ah ok. Well I can duplicate your error anyhow. I'm at a loss about what the problem is though. The following LotusScript code also errors out on LoginWithPassword. I didn't install a Win32 LastError function so I couldn't examine that.

Sub Initialize
    Set CS = CreateObject( "STComTk.CommunityService" )
    Call CS.LoginWithPassword( "Server", "username", "password" )
    Messagebox CS.IsLoggedIn
    CS.Logout
End Sub
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