IIS7 Module Only Works First Time? - asp.net

Question

I create an IIS Module that appends text to the page before it loads. When I go to the URL, this works perfect the first time the page loads. On subsequent loads, however, the text is never appended.
Any thoughts on how to remedy this?
== CODE ==
Here's my web.config:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<system.web>
<compilation debug="true" />
</system.web>
<system.webServer>
<modules>
<add name="MIModule" type="MI.MyModule, MI" />
</modules>
<caching enabled="false" enableKernelCache="false" />
</system.webServer>
</configuration>
Some module code:
public void context_PreRequestHandlerExecute(Object source, EventArgs e)
{
HttpApplication app = (HttpApplication)source;
HttpRequest request = app.Context.Request;
string pageContent = app.Response.Output.ToString();
string useragent = "HI!<br />" + pageContent + "<hr />" ;
try
{
_current.Response.Output.Write(useragent);
}
catch
{
}
}
and the rest of the code:
private HttpContext _current = null;
#region IHttpModule Members
public void Dispose()
{
throw new Exception("Not implemented");
}
public void Init(HttpApplication context)
{
_current = context.Context;
context.PreRequestHandlerExecute += new EventHandler(context_PreRequestHandlerExecute);
}
#endregion

Answer 1

Is the _current variable actually HttpContext.Current? Is it a static field in your module? When/how is it initialized? My guess is that the empty catch clause gobbles up all errors, and following that thought, you most probably get a null reference on _current. Try removing the try/catch to learn more on what's wrong with your code