grid=true doesn't compile

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Take any of the examples, and set grid=true
2. Try to compile with pdflatex or latexmk

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

Compile works. Poster is re-generated with grid. Instead, I get the following 
error:

! Incomplete \ifx; all text was ignored after line 632.
<inserted text> 
                \fi 
<*> poster_landscape.tex


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

* Current version, yesterday, 29 September 2011
* TexLive 2011

Original issue reported on code.google.com by [email protected] on 1 Oct 2011 at 2:57