I haven't played this game in ages, since before the final patch that changed the game a bit.. I just hit level 31 and does anybody else have this issue--- from level 1-30, when I level up a get a small boost to HP and MP plus my points to spend... When I hit 31, I LOSE about 10% of my HP/MP when leveling up... Is it just my game or is this a known glitch?

I just loaded an old save where my character was level 50. I used the console to give him experience points, enough to rise 2 more levels, and he got no more HP or Mana, but he lost none either. I don't know what the reason is, but he didn't lose any.

Edit: Here's something that may be of significance to you. Since I had loaded up the game, I was fooling around and noticed that when you get into fights with certain enemies, your health is reduced. And I don't mean injury, I mean the maximum health points. I got into some fights with mummies, necromancers, scorpions etc; things that poison or otherwise afflict you with some malady. My overall health was significantly reduced, and when the fight was over, I healed up fully yet my health was still less than it should have been. I had never noticed this when playing before, but then after roaming around for a time, I noticed that the original health had gone back to what it should have been. It seems that health can be reduced by afflictions, and will eventually be restored to normal.

Also don't forget equipped items that confer bonuses. If you unequip or swap them, it may appear as your stats have changed if one confers a vitality bonus, for example.

I have same problem. I am 30 lvl and after 31 i lose health and mana points. Before i had around 1900 HP and 5500MP. If i get 31lvl and after click on willpower, strenght ... or some skill, i get reduced to around 1600HP and 5000MP. I have TW 1 Epic Edition.

Very strange, i was thought the game is repaired.