ediff not finding diffs

[Eric Pement]

I'm having trouble getting ediff to properly compare two files. The
files aren't that large overall (20K each), but they do have very long
lines of up to 5,000 characters. There are differences in these files,
but ediff is displaying every line highlighted and not displaying the
contextual word changes.

>From reading the docs, I found a variable ediff-auto-refine-limit,
which is the only variable I can see that can be numerically adapted.
Will changing this enable me to compare very long lines, or should I
look elsewhere?

I run GNU Emacs 21.2.1 on WinNT.

--
Eric Pement