You need to make sure your Amazon API keys are set up properly in the following 2 places:
WordPress Admin Area > Tools > Datafeedr > Amazon API > Amazon Affiliate Settings
The Factory > Factory menu > Amazon API Settings (video
Here's how to find your Amazon credentials: http://www.datafeedr.com/docs/item/255
You can test that you are using the correct Amazon API keys here: http://associates-amazon.s3.amazonaw...pad/index.html
After you perform the above steps and have entered the correct Amazon API keys in both places, go here WordPress Admin Area > Tools > Datafeedr and click the [Update Products and Settings] button.
This should solve the 2 problems you are having; slow speed and error emails.