Acts_as_ferret not working with mongrel

Hi
Am using ruby 1.8.7 and rails 2.3.5
When a performing update or create on models am getting ferret error.
In my server app runnign with developemntmode + morethan one mongrel
servers.

Ferret::FileNotFoundError (File Not Found Error occured at
<except.c>:117 in xpop_context
Error occured in fs_store.c:329 - fs_open_input
tried to open
“/var/html/rails/buy/trunk/index/development/deal/_4b_0.del” but it
doesn’t exist:

):
ferret (0.11.6) lib/ferret/index.rb:285:in delete' ferret (0.11.6) lib/ferret/index.rb:285:in<<’
ferret (0.11.6) lib/ferret/index.rb:8:in synchrolock' /usr/lib/ruby/1.8/monitor.rb:238:insynchronize’
ferret (0.11.6) lib/ferret/index.rb:8:in synchrolock' ferret (0.11.6) lib/ferret/index.rb:267:in<<’
app/controllers/deals_controller.rb:184:in `update’

Can anybody help how to solve this