Slow query after upgrade from 8.2 to 8.4

Hello All.
We recently upgrade our server from PG8.2 to 8.4.
Our current version is:
database=> SELECT version();

version
--------------------------------------------------------------------------------------------------------------------
PostgreSQL 8.4.8 on amd64-portbld-freebsd8.2, compiled by GCC cc (GCC)
4.2.2 20070831 prerelease [FreeBSD], 64-bit
(1 row)

I read and setup most of the tuning advices.
Since the upgrade we have some very complicated reports that start
working too slow. Form tens of seconds to 1 hours.
I execute vacuum analyze before start the query.

Here I will post explain analyze. If you think it is necessary I will
post the exact query:
http://explain.depesz.com/s/J0O

I think the planner didn't choose the best plan. I will try to I rewrite
the query and set join_collapse_limit to 1 and see what will happen.
Meanwhile any suggestions are welcome.

Best regards and thanks in advance for the help.
Kaloyan Iliev