@two
That's called a typo.
I remember it was fixed in the last version of the calendar (hence the differences you mentioned).
Thanks for pointing it but to be honest it's not that important; even the graphics are not homogeneous because it's a collective work from fans not a professional one, though i think it's an awesome work.
Remember it was the first time the Summer Glau Wiki was doint this; having learned from this calendar, we hope to create an even more amazing calendar next year.
Help from artists and fans are welcome.

I can see differences between calendars.
The inspirational quote for April was :
“The survivors of the nuclear fire war called the Judgment Day.” Oops! (Calender-merged.pdf, 45MB, A3 paper)
“The survivors of the nuclear fire called the war Judgment Day.” Better. (2012Calendar.pdf, 5.3MB, A4 paper)

Correct link (without the dot at the end) : http://summerglauwiki.com/forum/6-132-6694-16-1312892973

All the indications to download and print your own copy of the Summer Glau Wiki Calendar can be found at the SG Wiki :
http://summerglauwiki.com/forum/6-132-6694-16-1312892973.

At TWO : the dimension of the graphics are 1191x1684 i.e. A3 size (double size compared to A4) but you can print it in A4 size to reduce the cost.

I have a printed version myself and the final result is awesome if you use a printing house with laser quality like i did.

That is AWESOME! I so want a copy

http://www.fileden.com/files/2008/8/13/2048723/2012Calendar.pdf
Summer Glau Wiki 2012 calendar; 13 pages with paper size of A4 (210 × 297 mm); download is 5.30MB
A4 paper has the same proportions as the original graphics, in case you wonder why this is not 8½"×11" paper.