Switching from headerbox to posterbox makes compilation fail

[GoogleCodeExporter]

What steps will reproduce the problem?

I had a poster that compiled when using headerbox environments, but I wanted to 
use some verbatim code. I read that posterbox would accept verbatim better. So 
I changed all my "headerbox" to "posterbox".

What is the expected output? What do you see instead?

I expected the document to compile fine.

Instead I got the following error:
-----
! Missing } inserted.
<inserted text>
                }
l.42 \end{poster}

-----

What version of the product are you using? On what operating system?

baposter.cls from 29/09/2011
compiling with pdflatex in Xubuntu 14.04

Please provide any additional information below.

The error is obtained even without even using verbatim. Reproduced using the 
attached file.

Original issue reported on code.google.com by blaise...@gmail.com on 2 Apr 2015 at 1:31

Attachments:

• minimal.tex