Cancelling a native DLL called from managed code

Hi,

My program, Visual Cobol managed code, calls an unmanaged DLL containing print routines using PrintEasy by Easirun. The call functions with no Problem, but, the Statement:

cancel "LSdruck" doesn't remove LSdruck.dll from Memory resulting in a blank page being printed first on next call. A log Shows "newInstance" in the dll is only established on first call.

Is there a method of removing the dll from Memory other than the - not working - cancel Statement?