I think 2009 was still on version 2, but regardless, I am compiling to version 2, using VS2005, running in ACAD2010, which I know was written to 3 or 3.5. I have had no trouble yet.
When I changed references from 2009 ACAD to 2010, for some reason unknown to me the Studio required me to add a reference to the newer Windows PresentationCore version 3.00, but that is the only reference I have to version 3 files.
I believe the other comment about copy local is the most likely, but there are a few other potential causes for the commands not being recognized. (The class or module containing them must be public, and the subs themselves must be public, for instance)
As a matter of fact, I just noticed you said Public Function, but command methods have to be Subs with no arguments. I tried it on my machine and I get a binding error at runtime, as opposed to unknown command, so maybe you just typed Function in the post out of habit?
Also, if you are following along with the labs, then I don't think this is the problem, but if you got ahead of yourself and put in a class with the CommandClass attribute, Autocad will only find commands in that class. CommandMethods outside the CommandClass will be ignored.
Edited by: chiefbraincloud on Jan 13, 2010 2:07 PM
Ok, read more carefully... Now that I see you are using VS 2008, maybe cwitt had the right Idea, wrong version. (while I am able to compile to .NET 2, and run in 2010 built for 3, I don't think you could compile to 3 and run in something built for .NET 2, which could be happening)
Dave O.