Publication falls to inactive

Hi all
We are using a pull publication what works well. After a time, maybe next
day, the publication must be reinitialized again.
The duration property of the publication does not define a final date. I
could not find other properties controlling the activation state.
Is this a security issue why a publication falls to inactive?
Thanks for help, Jan
Pls have a look at the retention period for the publication, the transactions
and the history retention. One or more of these is likely to be being
exceeded.
Paul Ibison