I know this isn’t really a Cocoa issue, but since it took me a week to figure out why my system was hanging every other day I thought I would share my findings.
A bug in lookupd has become more pronounced since Apple updated Java this summer. I finally ran across an Apple Discussion that had a few helpful links for working around this problem.
http://discussions.info.apple.com/webx?128@616.XFiOa25eVvI.2@.68ba0290
http://www.stepwise.com/Articles/Technical/Lookupd.html
http://www.macfixit.com/article.php?story=20050921061826456&query=lookupd
–zootbobbalu