Hi, Sim.

Each time you select a different time period, the route for that period is used. If the route changes, then selecting a time period before that route change will show a different list of routers than the one after that route change.

In the data you have in your first post, hop 3 has two different routers involved. Before 2:43:43pm, hop 3 is using router 220.232.2.61. After that point, it's 220.233.2.53. The data is all in the save files, but at different times different routers are involved, so the data is split between these two routers.

If you want to combine the data into a single "node" (and ignore that fact that there was a route change), you can do that by following the instructions here:

http://www.nessoft.com/kb/65

Best wishes,
Pete