i have a problem with the SetAccountInformation function.

i have written a programm, that runs daily on 400 Computers.
this programm creates tasks, dependent on values in a database, which run under the Domain-Admin-Account and interact with the current user-session.
all users are only in the group Domain-User.

here is my problem.
on 90% of the computers this programm work fine.
on the other 10% of the computers, the account-information is not saved.
they are also not saved if i set the account information several times
diffuse is, that the computer where the programm work or work not, change daily.
it is also not depending from the operation system (Windows NT, Windows 2000, Windows XP)
other scheduletasks are not present on the computer.

if the users are local administrators the programm works on 100% of the computer.
it has no affect if i add the user to other local groups or change any user policy.

i hope anyone can help me - i'am very hopeless.