As for chat see these 2 threads:
http://www.gnutellaforums.com/showth...threadid=29102 http://www.gnutellaforums.com/showth...threadid=29645
As for browsing, that phenomena sometimes happens to me too. I have no explanation why, other than perhaps the browse search runs out of energy/bandwidth or something. I don't know.
I originally thought that the Show incoming searches option box in the monitor window could control whether people were able to browse your shared library. However somebody suggested to me this is not the case. If that's the case then it just shows the search criteria, etc. of those people searching.