Allen,
I just ran Mozilla 1.2.1 and no problems. Now suffice it to say nothing in life is perfect.
Maybe there are some characters that made there way in there?
That would be my first guess or an upgrade to a newer Mozilla if its an older copy.
Try browsing my Photopost index and see if you see the same error. This will tell you whether its your version of Mozilla or not (If your not runnung 1.2.1) since I am posting to you and viewing that page with the new Mozilla. Would life not be simple if things were as easy as an upgrade.
Photopost Index