This is similar or identical to bug 156995.

Since the huge memory usage and the frequent runs of zmd interfers with some other work I'm doing, I often 'rczmd stop' the daemon.
Unfortunally, it seems to forget the service-lists from time to time.

I tried to reproduce it by:
- having no sl/catalogs available (don't know why)
- Adding them
- No load (memory/cpu) & rug returns -> zmd seemingly done
- rug sl / rug catalogs  show everything (even subscribed, which I didn't do this time explicitly, must have remained from previous time)
- rczmd stop
- waiting until the dust settles (rug ping->no zmd running, no load)
- rczmd start
- waiting again
- rug sl shows (this time) all services, but
- rug catalogs  shows none.

Screen log attached, I can attach zmd-messages.log or zmd-backend.log if needed; at least the former does not seem to contain much of interest.