Thanks for this info, Reg. Got it tracked down. <br><br>Summary: Any time a host is unreachable, it's creating a new temporary "host" placeholder for every request that's sent out for a hop after the last router that returns any data. Over the course of some time, this can be a substantial number - and each is filled with data up to the current sample (which is pretty dang painful in memory usage...). <br><br>This will be fixed in beta 2.<br><br><br>