Citations not inserted

Hi,

I've a fairly large document (35,000 words, 30 pages bibliography) and up until recently, Endnote and Pages '09 have been working great.

Now, I'm starting to encounter a problem with inserting citations. When I insert select the desired citation, it pauses and then inserts a "space"? If I double click the space it brings up the reference in the bibliography but I can't see it in the text.

Any ideas?