Recently, I took the task to migrate some of my application from 05 and make them 08 compatible. If you are familiar with orcus, then this is really no news to you until you do a consecutive down and up grade from targeting .NET 3.5 to 2.0 and then back to 3.5. If you tried that , you will get a bug as follow
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
Parser Error Message: Could not load file or assembly ‘System.Core, Version=22.214.171.124, Culture=neutral, PublicKeyToken=b77a5c561934e089’ or one of its dependencies. The system cannot find the file specified.
I realized that after the last upgrade, the IDE doesnt remove version 126.96.36.199 for System.Core but adds another assembly entry for version 188.8.131.52. Just take out the v 2 entry and you should be all set to go.