Workflows

I'm trying to build a basic workflow, to log errors - step one, where the user logs an error, the workflow marks the status as 'Open' and sends an acknowledgement email, works fine.

Step two however, gets stuck in an infinite loop. I want it to check when an item is modified, if there has been a response (Is the response field blank) and if there has, to mark the status as closed and send an email to the user with the response.

This is what I have for the workflow so far: