Deinstallation of website with msi does not remove inetmgr-entry

[cit42]

Hallo,

i have a msi that installs an ASP.NET website to IIS.
The MSI is produced by VS2005, using "Web setup project" and the "Web
deployment project".

The installation works fine, but after deinstall, the IIS-Manager
contains still the website-virtual-directory registered as application
and the bin-subfolder. The filesystem contains also these two folders.
All files and other folders are deleted correctly.

Does anyone know how to deinstall the website completly?

Greetings
Gordian

p.s. my MSI uses an customaction/installerclass that modifies the
web.config on install