administrator password changing sporadically.

We have several machines on our network, running w2k, that have batch
jobs that run at night. They depend on a service that logs in as
administrator to the local machine. On occasion, and fairly often, the
job fails because of a login failure.

Upon investigation I have found that the password to the local
administrator account has changed. It is always changed to the same
thing on all the machines. If I change it back everything may be fine
for days and then happen again, or it may happen the next day.

I don't know what is changing it. Cain & Able was able to give me the
password that it is being changed to, so that is how I know it is
always the same thing. SMS is running on the corporate network and I
suspect this is what is doing it, but getting answers at that level is
near impossible.

Group policy editor is set to never expire as is the account itself.

Any ideas?

Thanks,
Jim