Harvesting Proxies blocked

Hi,

last 5 days I have massive problems with harvesting on google engine. I work with 5 paid proxies, I can harvesting 3 minutes and IP is blocked for 12 hours.

Currently I work with settings "connection" harvesting 1, and "Delay in seconds" with 5.

Can you give me a helping hand here how I can harvesting again with the same speed?

Middle of December last year harvesting of 10k keywords was no problem, no delay in seconds needed.

thanks

Wolfgang