Restarting Slony crashes Postgresql?

Hi group,

I'm using Slony-I 1.1.5 with Postgresql 8.1.4 on 3 DB server (OS =
debian sarge).
I set a replication from a database on server A (master) to 2 servers B
and C (slaves).

Note that the slaves databases are in production and have a quite big
load.

I noticed last day that when I stop Slony daemon (for any reason) on a
slave server (B or C), a few seconds later, the server doesn't respond
anymore. Then I need to reboot the system. I noticed some "fetch 100
from LOG" queries on the master database too...

=> To prevent the server crashing, It seems that I need to restart
postgresql just after restarting Slony (and before it all crashes).

Is it always necessary to restart Postgresql after restarting a Slony
daemon ? (though, it doesn't seem necessary when the servers have not
many connections)

Any information will be appreciated.

Regards,
Nico