Returning CollectionBase from WebService

[Web Team]

Hi All,

I'm trying to build a webservice that returns a CollectionBase.

I am getting this error:

"You must implement a default accessor on
System.Collections.CollectionBase because it inherits from
ICollection."

I've searched and searched on this one - Plenty of articles, none of
which make much sense to me, the common thread seems to be that I need
to add some default properties. (I'm new to .Net - Help!)

I've pasted in my code below.

Many Thanks,

Simon.
<WebMethod()> _
Public Function GetAddresses(ByVal UPRN As String, ByVal USRN As
Integer, ByVal PostCode As String, ByVal PAON As String, ByVal SAON As
String, ByVal DesignatedStreetName As String, ByVal Easting As Integer,
ByVal northing As Integer) As CollectionBase
Dim AddressCollection As New OldInfra.BS7666.AddressCollection
Dim CollAddress As CollectionBase =
AddressCollection.GetAddresses(UPRN, USRN, PostCode, PAON, SAON,
DesignatedStreetName, Easting, northing)
Return CollAddress
End Function

[Web Team]

I've added the following code to both my webservice and
AddressCollection class. Hasnt made any difference :(

Public Property address() As Address
Get
Return address
End Get
Set(ByVal Value As Address)
address = Value
End Set
End Property