'Could not load the assembly' error on portal Site Settings page

[NewGuy25]

I'm getting an error on the 'Site Settings' page of the portal every time after I do an IISReset. This is the error:

Could not load the assembly 'Microsoft.SharePoint.Portal,Version=11.0.0.0,Culture=neutral,PublicKeyToken=71e9bce111e9429c'. Make sure that it is compiled before accessing the page.

I seem to get this error on every page in the _layouts directory but there may be exceptions I'm not sure. I don't get any error on the main page of the portal (ie the root).
The error goes away if I restart the server, but it happens again if I do another IISReset. Any ideas anyone?

 

[ChaserNL]

I dont now why this happens, but instead of an IISReset you could just recycle the App pool of the website? This has the effect of a reset in most cases but only for that site... See if the problem still happens.