Postgres on Linux Cluster!

I have recently transfered a big database on my master node of a 4 node openSSI Cluster... The system is working fine but sometimes, I get following errors:

http://192.168.1.100/cgi-bin/search.py
  File "/usr/lib/python2.2/site-packages/pyPgSQL/PgSQL.py", line 3067, in execute, referer: http://192.168.1.100/cgi-bin/search.py
    self.conn.conn.query('ROLLBACK WORK'), referer: http://192.168.1.100/cgi-bin/search.py
libpq.ProgrammingError: no connection to the server, referer: http://192.168.1.100/cgi-bin/search.py
, referer: http://192.168.1.100/cgi-bin/search.py

This error comes while insertion of data takes place...
Is Postgres successfull on Cluster??? Will that give me performance enhancement in any way??? Please help...

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Thanks and Regards,
GSS