Cathal,

• All virtual directories were either created by DNN or by Visual Studio. In my case it is Visual Studio.
• Inheritance is on the sub directories.
• However, Inheritance is on the Virtual directories.  Is this an issue?
• As mentioned earlier, the fully qualified real path names are 75 to 95 characters.
• This is a DNN 7.2 upgrade from a DNN 7.0.5 clean install on Windows 7, IIS 7.5.
• All my modules were placed in the directories via windows copy from a backup.
• I do my development directly in the deskopmodules directories.
• Visual Studio was used to turn them into Virtual directories.
• DNN became aware of the modules via Create New Module from Manifest.  The Manifest only told it about the controls and the associated ascx files. DNN was never made aware of the other directories, AFIK.
• As a result, Firefox debugger reports Module.css files in each module directories fail to load.  All image files, css files and jscript files in directories under the module directory behind desktopmodules fail from over 15 modules. 
• One image directory I created off my project folder behind desktopmodules works fine.  '/DesktopModules/XxXxx/Images'  I never told DNN about this directory. It is not a virtual directory.  It has the same windows property security permissions as all my other directories that work and don't work.

I did not understand the file GUID point you were making, so I can not comment on that.  I do not know where to look to see or tell you about those.

 I hope this helps to further clarify the issue.

Paul - are you saying that you have virtual directories inside the desktopmodules folder ?
And that it is these folders that you are having trouble accessing ?
Are you running the advanced url manager ?

Bump/Kick - Still needing a solution.