Seamonkey and unwanted window DOCTYPE

[bof]

I have been trying to convert to SeaMonkey as my browser to replace 
Mozilla for some time now and have found that when trying to use it, I 
have a window taking about 1/5 of the screen at the bottom that contains 
the message

 <!DOCTYPE overlay SYSTEM "chrome://imagezoom/locale/imagezoom.dtd">

A search of Google about three weeks ago located a page that gave 
instructions on how to get rid of this by renaming a file or a 
directory/folder, IIRC. They worked but I was not smart enough to print 
them out at the time. Now those instructions are not showing up in a 
search. A search of Bugzilla also comes up negative.

How can I get rid of this window --- it shows up under both FC5 and 
Windows XP, BTW.

BOF