cant get class module to work to change colour of active field

I've created a class module which is used to change the colour of the active field in a user form. The the sub within the module is called I get the error "wrong number of arguments or invalid property assignment".

The class coding us as follows:

 Option Explicit

 Public Event GetFocus()
 Public Event LostFocus()

 Private strPreCtr As String

 Public Sub CheckActiveCtrl(objForm As MSForms.UserForm)

 With objForm
      If TypeName(.ActiveControl) = "ComboBox" Or TypeName(.ActiveControl) =             "TextBox" Then
        strPreCtr = .ActiveControl.Name
        MsgBox strPreCtr
        On Error GoTo terminate
        Do
            DoEvents
            If .ActiveControl.Name <> strPreCtr Then
                If TypeName(.ActiveControl) = "ComboBox" Or _
                TypeName(.ActiveControl) = "TextBox" Then
                    'can only raise events that are declared as Public    Events within the Class
                    RaiseEvent LostFocus(strPreCtr)
                    strPreCtr = .ActiveControl.Name
                    RaiseEvent GetFocus(strPreCtr)
                End If
            End If
        Loop
     End If
 End With

 terminate:
 Exit Sub

 End Sub

I declare the cls in the form activation

 Private Sub UserForm_Activate()
 Set objForm = New clsCtlColor

and then call the class sub

 ActiveControl.BackColor = &HC0E0FF
 objForm.CheckActiveCtrl frmNewJob

this is when the error is received. ""wrong number of arguments or invalid property assignment". Any suggestions as to why this is happening would be greatly appreciated.