FeedBurner had trouble retrieving your Source Feed: http://omundodoscelulares.com.br/feed
The error message is:
com.google.net.rpc3.RpcException: /DNSDemux.Resolve to 172.20.0.160:54 [DEADLINE_EXCEEDED]
com.google.net.rpc3.RpcException: /DNSDemux.Resolve to 172.20.0.160:54 [DEADLINE_EXCEEDED]Actions you can take:
Validate your Source Feed with Feed Validator. This service provides additional detail about the problem, and how to repair it.
Resync your FeedBurner feed once you have repaired the source feed.