Service accessing mapped network drives

[Daniel Tak M]

I have a service (running under an user account) which needs to access several mapped network drives. It actually worked w/o problems in the past, but now it can't access them anymore. I've read that a service should not access such drives under XP, but that's not really "helpful". So my question is, is there a solution for this? And was there an update for XP that might have broken things? Thanks in advance.