The Logging Application Block does not control the AppDomain name, and
in ASP.NET running on IIS those are the app domain names.
You could create a custom listener to perhaps strip the extra stuff off
the app domain name or configure an arbitrary "app id" to use instead of
the app domain name. We've done the latter for SLAB's sinks (that's in the
latest EntLib v6 - you can download the source and take a look from here).
For a tutorial on how to build a custom listener, see these hands-on labs.