Seems a bit unusual - the clients should presumably have picked up the new sitelist...
What happens if you try the "add a dummy distributed repo - then remove it" trick? This will force ePO to update the sitelist version. Then do a wakeup call to a client - you should see it report "new sitelist" in the agent log?
thats a good idea I'll give it a go after lunch
that seems to have done it.