Windows Server 2003 sp2 kills ASP.NET 1.1 web applications

We recently updated our intranet server (Windows Server 2003) to the latest and greatest fixes including 2k3 sp2 and latest for every .NET version.

We have a variety of technologies that we use, including COM +, ASP, ASP.NET 1.1, ASP.NET 2.0, and ColdFusion. So testing can be, well, interesting as these technologies don't always mix well.

We have already applied the hotfix to resolve the COM + issue. The current issue is that ASP.NET 1.1 web applications just don't work. Any aspx page just throws the generic page not found error; static files (like .html) are returned as usual. The identical code still works correctly in our unloaded test environment.

Virtual folders are configured to run in their own application pool (separate from ASP.NET 2.0). The only one found by google clue I found was to change .NET to 2.0 for a virtual folder. It seems to work, but I'm worried that it will be hosing the server (as this happened in the past when someone accidentally did not configure the .NET application pool correctly).

While our plan is to complete the upgrade of existing apps to 2.0, this will not happen in the near term. Is there a hot fix that eluded my search? Or perhaps some other work around what someone has implemented?

Additional Information:

Both specified servers are 32 bits. Here is a snippet from the IIS log for the 404 error:

2008-11-25 23:58:41 10.150.1.31 GET / revenue / MailerAdmin.aspx - 80 - 10.1.3.18 Mozilla / 4.0 + (compatible; + MSIE + 7.0; + Windows + NT + 5.1; + MPI + INTERNAL; + InfoPath.2; + .NET + CLR + 1.1.4322; + .NET + CLR + 2.0.50727; + MS-RTC + LM + 8; + .NET + CLR + 3.0.04506.30; + CLR + 3.0.04506.648 ; + MPI + INTERNAL; + .NET + CLR + 3.0.4506.2152; + .NET + CLR + 3.5.30729; + MPI + INTERNAL) 404 2 1260