should be better now, right? The thing is that there are two different systems running in the background: the live system and the historical.
Sometimes the live system goes a little nuts when something happens with the infrastructure (e.g. the network is overloaded since some servers decide to move loads of data back and forth). That's when you observe weird stuff on the website like rates dropping to zero.
Anyway, that should only affect the last hour because every full hour the data gets re-processed by the batch (historical) system which cleans up everything. That's why at some point everything looks fine again.
The spikes in your range are due to aircraft sending broken positions. We'll implement smoother filtering soon to get rid of them.