If you have access to it the 3.5 book "The Book of Exalted Deeds" has rules for redeeming evil magic items...might have something on cursed ones too.
Cool, I'll look into that.
Thinking about it some more, magic items and spellcasting in general could be compared to computer programming. The magic item is the hardware and the magic is the software.
Cursed items are like magic items running malware or seriously faulty code.
Artifacts are magic items running extremely advanced code that can't be hacked or backward engineered by any known means. Artifacts themselves can't be destroyed except by a method unique to that object and generally as difficult to achieve as it would be to obtain the item in the first place.
Perhaps the process of 'mending' a cursed item is similarly unique, though not much harder to accomplish than creating the item itself. For example, a Bag of Devouring could be changed back to a Bag of Holding by 'feeding' it a golem (any type) bound by Dimensional Shackles, whose immunity to magic prevents the golem's consumption and whose bindings prevent the bag from simply ejecting the golem onto another plane.