yap - your right - the Caption gets changed but its not being refreshed (if you "wipe" another window over top of the form, you will see that change). The refresh property doesn't work (this needs to be fixed too), but if you "reshow" the hyperlink - it works, example:

code:
$b.onclick="$$t.caption='test' $$t.show"

Will fix all this in 2.0.4

-Shawn