Version 8.3.5 contains a variety of serious bug fixes. Among them you'll find:

• A back-end crash when client encoding cannot represent a localized error has been repaired.
• A fix has been applied to avoid a possible crash when deeply nested functions are invoked from a trigger.
• A fix to the GiST (Generalized Search Tree) index prevents corruption due to marking the wrong index entry "dead" after deletion. In the past, the corruption resulted in index searches failing to find rows they should have found.
• A repair for issues with mis-expansion of rule queries when a sub-SELECT appears in a function call in FROM, a multi-row VALUES list, or a RETURNING list.

A dump/restore is not required for those running 8.3.X. However, if you are upgrading from a version earlier than 8.3.1, see the release notes for 8.3.1.