I'm having the same problem, although with a slightly different ruby
version:
/usr/lib/ruby/gems/1.8/gems/hpricot-0.8.3/lib/hpricot/parse.rb:33:
[BUG] Segmentation fault
ruby 1.8.5 (2006-08-25) [x86_64-linux]
This is running the "premailer" command line tool, which uses hpricot.
Michael