<p>We develop Java Web-aps (Websphere, DB2) which display graphical and databased information. We would also like to offer the same application offline (distribution via CD/DVD) with online data-update. We have tried a number of alternatives in the past, but nothing has been really stable. What are the new best practices to take a Web ap plus data (in a small database) offline?</p>

I don't know how well it works with the CD/DVD distribution front, but the first thing that comes to mind is
Gears
. On the .NET side of the fence there's
Silverlight 2
. Then there's the
Mozilla Prism
project, although I don't know how far advanced that is.
These are all designed for not just offline access, but mixed offline/online, talking to a server when it's available and working locally when necessary.