Planner choosing nested loop in place of Hashjoin - Mailing list pgsql-performance

I have a query which is taking roughly 10mins to complete and the query planner is choosing a nested loop.

query and query plan with analyze,verbose,buffers

Disabling the nested loop on session is allowing the query planner to choose a better plan and complete it in 2mins.Stats are up to date and analyze was performed a few hours ago.

Any suggestions on what is causing the planner to choose a nested loop in place of hash and how can we get the query to choose a better plan without disabling the enable_nestloopenable_nestloopenable_nestloop enable_nestloopenable_nestloop?

Thanks 

Praneel