Hi LadyWolf
As long as you don't use any version 6 specific features, you
should be able to reasonably easily move projects. Basically, if
you touch an X5 project using 6, 6 will make it its own by
converting the project database file. Once this happens, you may no
longer use X5 to directly open the project.
Here's a workaround. Edit the project using 6 and make the
final step before you close to compile a .CHM using the Microsoft
HTML Help layout. Back in X5, open the project via the .HHP file.
This is a file type needed by the Microsoft HTML Help Compiler.
RoboHelp should advise that it sees an existing .XPJ and ask if you
wish to use it instead. Just ignore it and RoboHelp will open the
.HHP and rebuild a new .XPJ file for you.
Hopefully this helps... Rick