Cannot syntax-propertize because of narrowing

When I C-<LEFT-MOUSE-BUTTON> in a particular dvi file, the corresponding
tex file loads in an emacs buffer successfully but I get the message:

Cannot syntax-propertize 352840..415556 because of narrowing!

I wasn't aware that I had narrowed the buffer, so I'd be grateful to
receive some pointers as to how to debug the problem and find what is
causing widening. What do the numbers 352840..415556 refer to? The issue
seems only to occur at the end of the dvi file. The tex file is about
12,000 lines long. I'm using AucTeX if that's significant.


Colin Baxter.