asp.net 繁体环境下简体转换繁体

我的程序在简体环境下可以转换成功，但是在繁体环境下转换后都是乱码，这是什么原因？怎么解决？
方法如下：
1、配置文件：<httpModules>
<add name="StrConvHttpModule" type="HttpModules.StrConvHttpModule, ClassLibrary1" />
</httpModules>
2、ClassLibrary1.dll是两个文件编译出来的：
第一个：
using System;
using System.Collections.Generic;
using System.Text;
using System.Web;
using System.Collections;
using zhuanhuan.IO;

namespace HttpModules
{
public class StrConvHttpModule : IHttpModule
{
public string ModuleName
{
get
{
return "StrConvHttpModule";
}
}

public void Init(HttpApplication application)
{
application.BeginRequest += (new EventHandler(this.Application_BeginRequest));
}

private void Application_BeginRequest(object sender, EventArgs e)
{
HttpApplication application = (HttpApplication) sender;
HttpContext context = application.Context;
context.Response.Filter = new StrConvFilter(context.Response.Filter);
}

public void Dispose()
{
}
}
}

第二个：
using System;
using System.Collections.Generic;
using System.Text;

namespace zhuanhuan.IO
{
using System;
using System.IO;
using System.Web;
using System.Text;
using System.Globalization;

using Microsoft.VisualBasic;

public class StrConvFilter : Stream
{
private Stream _sink;
private long _position;

public StrConvFilter(Stream sink)
{
this._sink = sink;
}

public override bool CanRead
{
get
{
return true;
}
}

public override bool CanSeek
{
get
{
return true;
}
}

public override bool CanWrite
{
get
{
return true;
}
}

public override long Length
{
get
{
return 0;
}
}

public override long Position
{
get
{
return this._position;
}
set
{
this._position = value;
}
}

public override long Seek(long offset, SeekOrigin direction)
{
return this._sink.Seek(offset, direction);
}

public override void SetLength(long length)
{
this._sink.SetLength(length);
}

public override void Close()
{
this._sink.Close();
}

public override void Flush()
{
this._sink.Flush();
}

public override int Read(byte[] buffer, int offset, int count)
{
return this._sink.Read(buffer, offset, count);
}

public override void Write(byte[] buffer, int offset, int count)
{
if (HttpContext.Current.Response.ContentType == "text/html")
{
Encoding e = Encoding.GetEncoding(HttpContext.Current.Response.Charset);
string s = e.GetString(buffer, offset, count);
s = Strings.StrConv(s, VbStrConv.TraditionalChinese, CultureInfo.CurrentCulture.LCID);
this._sink.Write(e.GetBytes(s), 0, e.GetByteCount(s));
}
else
{
this._sink.Write(buffer, offset, count);
}
}
}
}