Hi,
a useful feature of the former Stackz was beeing able to use the Kanji Info and Dictionary for a displayed entry, while testing or
learning.
This does not seem possible in the 2007 Stackz: if you press F8/F6 while testing/learning in order to bring up the respective function
the window stays in the background so that you first have to end the testing/learning to see the result of the search.
Compared to just press F8/F6 in order to bring up the option, and Esc to close it again this is an undesirable change.
It only stays in the background if it is docked.
Note that you can undock it even if the study dialog is open, there is no need to close it.
Edit: it does come to the foreground, but only with the mouse - not with the keys, as you correctly wrote.
This has been modified on purpose, see this thread:
http://www.stackz.com/forum/index.php?topic=211.0
It might be redesigned later, but not in this release.