how to change drupal file path ?

hello everybody ,

after i upgraded from drupal 5 to 6 i dont see the pictures of old entries anymore .
i know that the problem lies in the path specification of my files directory .

in old entries the path to images looked like this : src="/files/u1/pictures/private/bike.01_small.jpg"

but now i have to put the absolute path to see the pictures again :
src="/website/files/u1/pictures/private/bike.01_small.jpg"

does anyone know where i can specify the path so i dont have to change the link to every single picture by hand ?

thanks in advance,

b.