Heroku - Locomotive Wagon Assets dissappear

Hi,

We currently have our website running on Heroku using the new wagon and professional dyno (www.careerseekers.org.au) .

After a day or two, the Theme Assets on the wagon dissappear, and shows our public website without any style or theme, like its just the plane HTML being rendered.

Is this a bug on the wagon? or would this be an issue on Heroku?