Still having panel problems

[Grant Gould <ggould alum mit edu>]

A user of mine is having panel difficulties which I mentioned earlier
(short version: panel doesn't start but instead says that there is a
panel alrady running, when in fact there isn't).  Apart from some
suggestions about WindowMaker (which I don't have installed), nobody
was able to figure out.  I've been chasing this problem without any
luck for a while now.

My question is, how does the panel determine that it is "already
running"?  Is there some sort of lockfile or pid-listing file?  Does
it search the process table?

Anyone know the answer to this?
 --Grant Gould