NO. The servers are idling miners today. THAT is why. The drop is TOO severe.
That usually means connection problem (big latency).
Looking to your signature (2 workers = 600+Mhs) make me think you have 2 powerful miners ... so you need o good network latency or configure better your miners (try to get more work doing more getwork requests and buffer them).
Ciao
NVM ... Just looked at poolpush server code ... it seems that you can't buffer requests (will fail the submission of the result).