These things you must do, or it won't work at all:
- You must add the useLegacyV2RuntimeActivationPolicy="true" attribute to the startup node of your app.config file. Without this, you'll get an exception at runtime indicating that the mixed-mode assembly can't be loaded without additional configuration. This setting changes the way the Framework loads assemblies in side-by-side mode when they use APIs such as COM interop; marklio explains this better than I.
- You must apply the machine.config changes in my prior post to the machine.config for both the 32 and 64 bit versions of the Framework, or you must change your build configuration to target a specific CPU architecture. You need to do this so the WCF architecture used by the Adapter Pack can see its binding extensions in the appropriate architecture.
The potential issue is that the Adapter Pack seems to be slower when run under Framework 4.0. The performance hit, based on my instrumentation in an application that I've just migrated, is about 20% or so for the SAP RFC adapter. I suspect this is because of changes between the 2.0 and 4.0 CLRs. Depending on what you use the Adapter Pack for, this may or may not have a major impact. SAP, for instance, is often slow enough on the RFC interface that a 20% increase is hardly noticeable.
Oh, and this trick works for both the full and client profiles of the Framework, again assuming you do both 1 and 2 above. 2 will usually be taken care of for you as most of the time, you'll be using architecture-specific DLLs for your ERP system's interface and you'll have already addressed this when you built the application.