Actually Jim, it was simple problem, with no real solution... As the original App was developed using the .Net Framework v1.1, when it first loads, that is the version of the framework that is loaded. Then, when my DLL is loaded (externally, after the original app is loaded) it fails, because it is looking for the .Net 3.5 framework. The solution would be to force the original App to run under the .Net 3.5 framework (which is entirely possible, with an App.config change) and then my add-in would also run at that level. But the original app "breaks" when I do that, and I don't currently have access to the source code of that app. I may at some time, but for the time being, it looks like I have to stick to .Net 1.1 development for this case. Sorry for the distraction guys... Glenn Sullivan, MCSE+I MCDBA David Clark Company Inc. ________________________________ From: windows2000-bounce@xxxxxxxxxxxxx [mailto:windows2000-bounce@xxxxxxxxxxxxx] On Behalf Of Jim Kenzig ThinHelp.com Posted At: Monday, February 18, 2008 4:40 PM Posted To: Windows 2000 Conversation: [windows2000] Re: OT: .Net Programming Versions Subject: [windows2000] Re: OT: .Net Programming Versions Where are you locating the dll, I seem to remember something about it being different for vista as to where it should be. Try placing it in the same directory as the app. Jim On Feb 18, 2008 3:07 PM, Sullivan, Glenn <GSullivan@xxxxxxxxxxxxxx> wrote: Sorry for the OT post... I have a package running my media at home called MediaNet. It is extensible by writing your own modules, and in particular, I am trying to add a new kind of Interface Module. There is little documentation, so I am kind of flying blind... The MediaNet package itself (and all of the built in interfaces) was developed in VB 2003. If I try to create the Interface (as a compiled Class Library DLL) in VB2003, no problem. It loads correctly. If I build the same interface DLL in VS2008, no love... the module starts to load, but never even gets to the "Init" method before it is unloaded. Unfortunately, the base application is a services, so I get very little in the way of error reporting. But I don't think that the application is actually calling the DLL at all... It appears to be incompatible, and I'm not sure why. Does anyone have any experience developing a Class Library DLL using a later version of VB than the calling application? I thought that was kind of the goal of Class Libraries: make the code more portable and modular, no matter where the DLL is used later. Am I missing something obvious? I feel stupid... Glenn Sullivan, MCSE+I MCDBA David Clark Company Inc. ***************************** New Site from The Kenzig Group! Windows Vista Links, list options and info are available at: http://www.VistaPop.com <http://www.vistapop.com/> ***************************** To Unsubscribe, set digest or vacation mode or view archives use the below link. http://thethin.net/win2000list.cfm -- Jim Kenzig Microsoft MVP - Terminal Services http://www.thinhelp.com Citrix Technology Professional CEO The Kenzig Group http://www.kenzig.com Blog: http://www.techblink.com