Try quicklook on a file you just edited. Does that work?
I noticed that quicklook won't show the contents on Pages documents that were created with an older version of Pages. In my case the break point is somewhere between early 2006 and mid 2006 which is when I would've upgraded from iWork '05(Pages 1) to iWork '06(Pages 2). This is on Mountain Lion.
I am guessing the Pages quicklook on Mavericks may have a different cutoff for what will show.