I've been fighting with IIS the last few days and the error that IIS generates is:
Message: Unable to find assembly 'FluentNHibernate, Version=188.8.131.523, Culture=neutral, PublicKeyToken=8aa435e3cb308880'.
What's strange is that if I check in procmon, I can watch the IIS process find the dll in the directory where I would expect it to find it, and then it continues to search other directories for the exact same dll. It is also searching for the PDB for some reason for the DLL. The DLL also exists in the temp directory that IIS creates:
C:\Windows\Microsoft.NET\Framework\v4.0.30319\Temporary ASP.NET Files\ws-sm\bc2df7a7\729516d\assembly\dl3\42ab9d3b\00d491a3_3e6bcd01\FluentNHibernate.DLL
So it was clearly able to copy the dll to it's running location, but it reports it can't find it.
I checked all of my web.config files and compilation debug is set to false in all cases so I'm surprised to see it looking for pdbs.
Googling this error didn't return anything useful.
I'm using Win2k8 x86 with IIS 7 and my application pool is ASP.NET v4.0 Integrated.