i dont know if this is cheating (gee bugs are sometimes helpful) but i found out that the lich in the city gate can be killed twice. i went inside his room and had a fight with him, unfortunately i have to exit the room because two of my mages are dead so i have to revive them. when i went out, the mage went out including the demon he summoned. i killed him and looted his body. whe i went inside his room to loot the sarcophagus, he is there standing in flesh and blood (does a lich have them?) with his pet (the devil he summoned) so i have to "sushisize" him again (new term meaning to turn into sushi)... after a long session, i looted his body and found the same things i looted from his body (alter ego) outside the room. did anyone encountered the same?

i discovered this when i installed tob

No its a bug with the game it happens with most of the baddies if you leave them during a fight they will follow you out of the room but for some reason they are still in the room in other words it duplicates the baddies.

It can be fixed with the latest patch from Bioware

It's an interesting bug but IMO any bug is a bad one. I thought it may have been a project image or similar spell that you killed which made you think you killed two lichs but the fact that both dropped items would seem to disprove this theory so it's a weird one. You should probably install the offical bioware TOB patch if you haven't already to stop any other weird bugs rearing there ugly heads.

Of course, in theory you could "kill" a lich an indefinate number of times if you don't destroy its phylactery.... phylactiry... Its life-force-house-thingy. Fortunately for everyone concerned, the oh so powerful Kangaxx didn't think of making one for himself and putting it in some super-protected place..