Chnge in shutdown behavuior of me new (late 2013) MacPro after loading 10.10.3 update

Hi,

I just upgraded my New MacPro to 10.10.3 and now instead of quickly shutting down it sort of hangs with the display screen dimmed for 30 seconds or so before shutting down.

I loaded the update from the APP store and not the 10.10.3 combo update, which I have since found.

After the update was loaded I made sure to repair permissions on the SSD.

Does the New MacPro require a special update?

Should I try the update again, but this time using the Combo update?

Thanks