Screenshots are appearing and then going again

[Dave Morley]

Bug Description:
If you go to an application that is in the repos rather than DP/SCA the image appears for a split second and then disappears

Comment from noodles on irc:
<noodles> davmor2: chromium. But the js seems to have set the img src to http://screenshots.ubuntu.com/screenshots/d/deja-dup/8643_large.png
<noodles> which is giving a squid error.

UWC Version:
Django 1.3
Python 2.6.5 (r265:79063, Apr 16 2010, 14:15:55) [GCC 4.4.3]
preflight 0.1
openid 2.2.1
piston 0.2.2

OS:
64bit Precise

Browser:
FF 13.0

Problem URL:
https://apps.ubuntu.com/cat/applications/deja-dup/

Steps To Reproduce:
1. goto the link above give it a second or two
2. note the screenshot then disappears

Expected Result:
I expect to see a screenshot