Sometimes the Restoration spell heals you twice, sometimes it heals you three times. This was a bug back in the alpha which got fixed, somehow it got re-introduced.
This is a HUGE bug because Restoration is your only real source of magical healing until whenever you can get Mass Heal. It's a big deal if it's only 2/3 as effective as it's supposed to be.
Give how so many bugs have been "re-introduced" in EE, I'm getting the suspicion that EE is entirely built around a very early D:OS build, before patching.
Hopefully patching D:OS is faster and more consistent than D:OS:EE.
