OpenSolaris Build 127 brought Presto back online.

Some time ago, the presto-Framework for autodetecting printers in the
network was broken.

When a network device became online, the process hald-addon-network-discovery ate all CPU ressources.

The solution do this was to
svcadm disable svc:/network/device-discovery/printers:snmp
disable the printer discovery service.

With Build 127, the service can be set active again:
svcadm enable svc:/network/device-discovery/printers:snmp
The Notification windows for printers appear again on the screen.