Compiling Code Modules - Cannot write to output file

I am attempting to write a custom code module (*.kcm file). I can compile the code one time. All future attempts to compile result in the following error:

Compile Error: Imports Line 0: Could not write to output file 'e:K2PolicyToolPolicyToolBinModules.dll' -- 'The process cannot access the file because it is being used by another process. '

If I close K2 Studio and manually delete Modules.dll, I can compile again. However, this only works one time. Then I have to close and delete again.

It appears as if K2Studio is never releasing its reference to Modules.dll.