Image quality on the web is a complex topic.  Scaling in Publisher can indeed
give you problems like moire patters, and a weird solarization effect.  What is
more, just cropping in Publisher sometimes can produce the same undesired
effects.  Everything looks fine until you publish to the web, only then do you
want to kill somebody on the Publisher development team.  While I have read
dozens of axioms that if you follow them, are supposed to solve the problems,
none always prevent surprises in my experience.

For starters, do image resizing in a program like Photoshop with a "save for the
web" type feature.  Photoshop Elements is priced for the less dedicated use, and
the sticker shock is less likely to cause a heart attack.

Perhaps some of the MVP genii in here can shed some light on this problem.  I
have learned through trial and error how to fix the problem once I see it, but I
have not a clue how to reliably predict it even.  I see variations of this
phenomenon on even professionally done websites from time to time, sites I am
sure were not generally done in Publisher.

Mark,

Perhaps use JPG images instead of GIFs for better resolution.

DavidF