auctex - no valid bibliography?

[Tyler]

Hi,

I have a problem with auctex mode. I just saved my current document and 
.bib file so I could close and restart, to test a new .emacs file. When 
I re-opened my .tex file I found I couldn't insert new citations:

C-c [

When I try, I get to the screen where I select what style of citation I 
want, but after I select it emacs reports:

"No valid bibliography in this document, and no default available"

I haven't changed anything in the bibliography commands, or the source 
.bib file, and it worked just five minutes ago. I can still compile 
fine, and the output is ok, including all the citations and the 
references. I just can't use the auctex features to automatically add 
more references.

Please help!

Tyler