Are those crashes happening as soon as you start
BearShare or while downloading?

At the bottom of the downloads view there are two
checkboxes for clearing completed and failed downloads.
Try clearing both of those boxes. There is a known bug with
that feature.

Panda has been known to fall apart under a full load. Try
uninstalling the whole Panda Suite completely for a short
while to see if BearShare stops crashing. If that solves it
then I can recommend a couple of stronger firewalls.