Magic Barrier itself isn't bugged, but the way it and the sight bonus skills on equipment are handled can rarely lead to errors recalculating the values when removing that equipment.
A reasonable number of bonuses (or even slightly excessive) shouldn't cause any problems. If the list of bonuses becomes large enough that the mouse over description goes off the screen, it can cause the game to crash. For individual bonuses, you can also cause problems with extreme values. A +200 boost to stats should be fine, for example; checking something with sight range I equipped one ring with a +1000 sight bonus ok (cleared much of the fog of war in the wastelands), but trying a second such ring crashed the game.
