I noticed that I get ping timeouts when pinging with “interval=10ms”. It seems only the reporting can not keep up with the speed, as a packet trace showed no missing ping reply’s. This was tested on ccr1009’s. When you say you have to use flood-ping to do that - indeed flood ping misses no packets, but I needed to set the source-address 
and so flood ping was no option.
When diagnostic tools do not work as expected, this can delay troubleshooting. Be careful when making decisions based on ping!