Images not rendering in template

I have a problem with an app, rendering the images that are set through a template that reads the src from a mongo collection.
The first time the page is loaded they appear fine, but when I move to a different route and then back. Images are not showing, url src are correctly set, so I don’t understand where this problem might be coming from. If I reload the page, sometimes multiple times, they are back again.
I’m using meteor 1.2.1

Below a snapshot of how they appear in my browser.

Would appreciate any hints on how to solve the issue

Can it be that you are not waiting for all the subscriptions used in your template to be ready? Can you show some code?