I realize that being upset about randomly having extra of a stat might seem odd, but having 15 extra mana regen makes mana pretty much pointless and has sort of ruined the fun of my character (who is not a mage). I'm not really sure what caused or is causing my extra mana regen or if this is a known bug. I haven't equipped extra belts or the like and have no talents (or even talent paths) that provide a mana regen stat. The only mana regen I have is a total of three on two pieces of gear, but the 15 extra is still on my character when I'm completely naked. I do have blood mana if that has anything to do with it. I can provide the save if it would be helpful.
Are you using Necronomiconomics? Alternatively, were you recently cursed a lot by Wights (undead head floaty things) just before you leveled up? There's a bug with the 'Curse of the Mind' debuff that causes you to get massively increases sagacity/magic-power/mana-regen. Usually happens when you have a large stack of these debuffs right before leveling up.
Thanks a ton for the reply. It helps a lot to know that it is a known bug and further to know what caused it. I had necronomiconomics and that is likely the cause.