Locating assemblies in ASP.NET

[Hilton]

An ASPX page in a virtual directory does not find the
compiled assembly containing the base class located in
the application's bin directory correctly.

Example:
1) Create project WebTest (http://localhost/webtest)

2) Create simple WebForm1.aspx that contains "Hello
World" and inherits from WebTest.WebForm1

3) Compile and then test by navigating to
http://localhost/webtest/webform1.aspx - form appears as
expected

4) Now create a directory elsewhere on the filesystem (I
used d:\temp\wt) and map a virtual directory from
http://localhost/webtest/wt to this location.

5) Move the WebForm1.aspx file into the directory that
the virtual directory is mapped to

6) Test by navigating to
http://localhost/webtest/wt/webform1.aspx - receives
error "Could not load type 'WebTest.WebForm1'"

Why does this not look in the
http://localhost/webtest/bin directory for the DLL??

Why does IIS treat a virtual directory differently to a
physical directory? (it works if wt is a physical
directory under the application)

I have tried messing with probing and codebases to no
effect.

I've tested this on XP and W2K Server with the same
results.

Thanks,

Hilton