Nautilus loses history

[rikona]

I like and use number of KDE programs. The Ubuntu website suggested
installing kubuntu-desktop instead of downloading several individual
KDE programs, so I did that. This may be the source of some problems
that were *not* there before this installation. [I don't use that
desktop though]

One new problem is that when Nautilus is minimized, it no longer
appears in the group of running programs brought up by alt-tab. The
only way to get it seems to be to click on the icon, but that brings
up a brand-new instance that has no memory of how it was before it was
minimized - no locations, tabs, etc. 

How can I get it to remember its state when minimized and to be in the
group of still running programs, so I can bring it back as it was?

I'm using dolphin, and that program minimizes and comes back
correctly. But, the running instances of dolphin appear as a *second*
dolphin icon. Is it possible that kubuntu-desktop somehow throws away
a competing file manager?

Thanks,

 rikona