We had an issue where Partial Purchase Orders (Project) was not posting proper cost amount to the Project accounts.
Microsoft has identified this behaviour as a bug - http://support.microsoft.com/kb/937246.
Note, the hotfix was in form of dis<layer>.aod file. I extracted the .aod file and merged it on the local AX instance running on my laptop, identified the classes which is required for the above fix, Did a compare and imported only the code which fixes the issue.
Just a FYI on the classes which were impacted: