The issue is with the current release of libgdiplus (2.11+git20131008.9732566-5ubuntu1)
Specifically, I think the change that broke things is this:
[5e251c5] Ensure PNG transparency values are initialized. Thanks to
Tom Hindle (LP: #1296786) (Closes: #741980)
As a quick and dirty fix, you can simply install the Saucy libgdiplus version.
I don't know enough about patching these sorts of things to figure out exactly what's broken though.
So, I've been doing some digging.
The issue is with the current release of libgdiplus (2.11+git201310 08.9732566- 5ubuntu1)
Specifically, I think the change that broke things is this:
[5e251c5] Ensure PNG transparency values are initialized. Thanks to
Tom Hindle (LP: #1296786) (Closes: #741980)
As a quick and dirty fix, you can simply install the Saucy libgdiplus version.
I don't know enough about patching these sorts of things to figure out exactly what's broken though.