So in baldurs gate I met this theif by the name of marek who apperently posioned me I tracked him down and found the antidote so I drack it (all 10m doses) and went on my merry way.. but then ten days later evry time I try to rest I die... what have I done wrong? did the anitdote not work? or is there more to the quest?

If you tracked down Marek and just killed him for the antidote, then it won't work. You must play out the quest.
Go here for a good way to handle this gamestopper....
http://www.geocities.com/sixospades/bg/bgguide.htm

You will need a savegame of before you were poisoned, or at least one of before you killed Marek.

[ 10-01-2005, 04:00 AM: Message edited by: ElfBane ]

is there no other way becus I have came very far in the game and I have no saved game before...

You can fix it in the console
CLUAConsole:SetGlobal("PartyCured","GLOBAL",1)
And if you ask me how to do that I have one answer: Google & IW Search.

Listen to the instructions that lathander gives you when he tells you that you were poisoned. He's not out to trick you.

And even if he was, you're poisoned and have nothing to lose. So follow his leads.