Startup panel problems

["Umair Yousufi" <ra9119 email sps mot com>]

I (sometimes) get the following error msg after gnome starts:

"I've detected another panel running.  Start another panel as well? (The
new panel will not be restarted)"

If I reply "yes", the panel starts normally.  If I reply "no",  the
panel is missing altogether (I'm a newbie and not having a panel left me
bewildered until I learned (from the archives) about the "panel"
command).  During the times I d/n get the error msg. the panel is
missing as well.  Typing "panel" works, but it reports something about a
GDK-error first.  

What is causing the initial startup msg, and how can I get rid of the
problem?  Someone suggested going to ~/.gnome/ and removing the session
file (as long as a default.session file exists).  This works for a
while, but the problem recurs, usually after I switch to a different
window manager (specifically Enlightenment).  After I switch, it asks
about saving the session now or later.  I find that saving now vs.
saving on logout produces that same startup error.

Anyway, it's not difficult to just hit "yes" or to type "panel", but I'm
still curious about how to get rid of the problem :o)

--
Umair Yousufi