Project and Project Server and SharePoint October 2007 Cumulative Update
Updates for Project Server 2007

This include a number of fixes, so Microsoft strongly recommends that you test this in a test environment based on your production environment before putting this fix live in production.

The article below provides information on how to deploy the Project Server Cumulative Update.

Deploy cumulative updates (Project Server 2007)

http://technet.microsoft.com/en-us/library/dd239177.aspx

Service Pack 2 for both WSS and Office Servers 2007 are required for this Cumulative Update. The KB articles below provide information on how to download and install SP2 if you have not already done so.

Note: The SP2 Requirement is new as of the August 2010 Project and Project Server 2007 Cumulative Updates.

Description of Windows SharePoint Services 3.0 SP2 and of Windows SharePoint Services 3.0 Language Pack SP2

http://support.microsoft.com/kb/953338

Description of 2007 Microsoft Office servers Service Pack 2 and of 2007 Microsoft Office servers Language Pack Service Pack 2

http://support.microsoft.com/kb/953334

The Server 2007 CU is released in two different versions. The first version is in Individual Packages specific to a particular product like WSS and Project Server. These are smaller downloads but they do not include language packs or patches for other products so patches for those products would have to be downloaded and installed separately. 

The second version is the Server Rollup Packages. This is a set of two rollup packages which contains all the fixes for WSS, Project Server and MOSS. These packages should be used when MOSS is part of the deployment and/or you have language packs installed. The Server Rollup Packages are much larger (~100MB each) but they will greatly simplify MOSS patch deployment.

You can read about the fixes included in the October CU from the following articles:

NOTE: Microsoft strongly recommends testing within a NON-Production environment prior to rollout.