Watch out when using @@IDENTITY and SCOPE_IDENTITY() in your applications. Below is a quote from a Microsoft SQL Server engineer.
… whenever a parallel query plan is generated @@IDENTITY and SCOPE_IDENTITY() are not being updated consistently and can’t be relied upon.
You can find more about the bug and workarounds at the SQL Server bug report.
UPDATE 28MAR2009: Pinal Dave has a more detailed blog post about the bug with workaround.