Working with .net helper classes in BizTalk Server is a common occurance.
It can sometimes be easy to forget to GAC the latest version of the code when you go to test the solution on your local development box. But using a simple Post Build Event, you can have your code automatically put in the GAC for you.
Adding a post build event is easy. Just go to the project properties of your helper class and select Build Events.
Enter the following under Post Build Event:
“C:\Program Files\Microsoft Visual Studio 8\SDK\v2.0\Bin\gacutil.exe” /i $(TargetPath)
Now when you build your .net code your dll will be GACed for you.