This one I might be able to answer more directly. Microsoft has incorporated
a "pop up blocker" in IE. If you don't want to use it you can disable it or
change the settings under Tools.

Publisher produces HTML code that is designed for IE, and sometimes it lacks
cross browser support. Some of these issues can be fixed, some can't. Some
people have no problem with their sites in Mozilla, others do.

Be sure to go to Tools > Options > and untick "Rely on VML..." and "Allow
PNG...". If you still have problems with the images, then you can try
changing your design around until you figure out why the images are not
displaying correctly, and perhaps why your navbars don't work. I know that
the horizontal navbars produced by the navbar wizard don't work correctly in
Firefox while the vertical navbar does, as does a hand built horizontal
textual navbar.

If you take my suggestion in your other post about Publishing to the Web, to
your hard drive, you can open and test the files in Mozilla, FireFox or IE.
Move around the images one at a time and see what you are doing design wise
that creates the problem with the images loading correctly. And...if it is
just a matter of the images loading but being low quality or distorted, that
may be explained by the fact that Pub 2003 produces copies of each image in
various formats with the goal of loading the best image depending on which
browser is used. Unfortunately that doesn't work very well in all cases.
Your only workaround then is to import the images into your page instead of
embedding them...

DavidF