We strive to preserve as much backward compatibility as possible each time we publish a new version.

Even with this goal, there are times where we need to make "breaking changes" - a change to the toolset that causes something that worked previously either to not work or to work differently.  We publish these breaking changes in our help documentation.  These changes are never made without reason - for instance, to fix a bug or to provide specific, new functionality.

Another important point is that NetAdvantage 2004 Volume 3 works with versions 1.0 or 1.1 of the .NET Framework, while NetAdvantage for .NET 2009 Volume 1 works with versions 2.0, 3.0, and 3.5 of the .NET Framework.  There are some changes to functionality in the framework itself, so you'll have to account for this as well.

We recommend that you thoroughly test your application after performing an upgrade, to make certain that everything works as you intend it.  If you find a difference in behavior that isn't listed as new functionality or as a breaking change, please submit a support request so that a Developer Support Engineer can assist you in resolving the issue.