ASP.NET "Could not load file or assembly App_Web..." Error

Dot .Net Dilemmas.
God, I spent a lot of time over the last few months looking for a proper solution for this one and at the end of the day, the best solution I found was to delete all temporary ASP.NET files, by removing the folders under

C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files

I closed down all instances of VS before doing this just to ensure that all the files were released so that they could be deleted.