I've been developing an ASP.NET application for quite some time now without a single problem and all of the sudden when I attempt to open the project in VS 2003 (it's an ASP.NET 1.1 app) I am greeted with the following dialog box:

I've been coping with the issue for a few weeks as I'm able to simply open the application directly in IE and attach the debugger as necessary.  Something must have changed of which I'm unaware, but this had me confused.  Needless to say, the very first thing I tried upon seeing this message was to register ASP.NET 1.1:

C:\>cd\windows\Microsoft.NET\Framework\v1.1.4322
C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322>aspnet_regiis -i

Investigating it beforehand with the -lv and -lk revealed that it was indeed already registered with ASP.NET 1.1, but I figured redoing it wouldn't hurt.

When I tried opening the project in Visual Studio, still the problem persisted.

The only solution that I could come up with was to create the file that VS looks for when opening a web project (get_aspx_ver.aspx) explictly in my web application's root, even though it's not expecting to find the file in the first place.

Has anyone else seen that and/or have a better solution?