Do you know which equipment causes this problem?
By combat stats, do you mean normal stats like attack, defense or sexual stats like oral exp, birth exp?
hp, mp, attack, defence, luck, and all the others. i noticed it when i put on a speed ring or a second speed ring, but that is not the only trigger. it seems like the game sometimes tries to load the stats and draws a 1 in stead which is then permanant. i am pretty sure it also happens somewhere along the way when i enter and/or leave the dungeon and/or somewhere from saving to loading the game.