sure there is the difference, because this bug (as you can see in mantis) only exists with mssql
@The_Stig:
In the mean time if you can do a test using MSSQL we could perhaps have some more feedback. Testing on virtual PC should be fine too. I did my tests using MSSQL 2005 Express not 2008, but I highly doubt it is an issue of 2005 vs 2008 as that would mean a great deal of applications using datepart() would break when upgrading to 2008.