wsdl error of mulitiple asmx with reference to one shared dataset

[wc_chan]

I wrote a web service projects having 2 asmx and 1 dataset, says dsTest1.
The amsx will have a parameter of the dataset as follows:

in 1st asmx:
<Wethod()HelloWorld1 (byval a1 as dsTest1) as string

in 2nd asmx:
<Wethod()HelloWorld2 (byval a2 as dsTest1) as string

When I ran wsdl for the dynamic discovery file, vsdisco, I got the following
error:

Microsoft (R) Web Services Description Language Utility
[Microsoft (R) .NET Framework, Version 2.0.50727.42]
Copyright (C) Microsoft Corporation. All rights reserved.
Schema validation error: Schema with
targetNamespace='http://tempuri.org/dsTest1.xsd' has invalid syntax. The
global element 'http://tempuri.org/dsTest1.xsd:dsTest1' has already been
declared. Line 3, position 4.
Schema validation error: Schema with
targetNamespace='http://tempuri.org/dsTest1.xsd' has invalid syntax. The
identity constraint 'http://tempuri.org/dsTest1.xsd:TestTableKey1' has
already been declared. Line 16, position 6.
Warning: Schema could not be validated. Class generation may fail or may
produce incorrect results.
Writing file 'D:\Program Files\Microsoft Visual Studio
8\SDK\v2.0\Service.vb'.

There's no problem when I did wsdl for only particular asmx. It seems that
wsdl processes twice for the dataset. Note: There's no problem for dotnet
framework 1.1. The problem becomes hurdle of our migration project.

Please kindly help.
Thanks in advance.