I'm not getting email Update Notifications on Bugs

I'm not getting email Update Notifications on Bugs

If I create a ticket, I will receive an email notification. If someone responds or comments on the ticket, I am not receiving notifications. I am "following" the ticket, and all my notifications are set to on in my profile. I double checked SPAM and there's nothing in SPAM. I am using Google apps for email.

What would prevent me from receiving notifications?