Thanks for the input Richard, but the Favicons that are displayed with my
"Favorites" (aka Bookmarks) and in my "History" weren't what I was referring
to.

I guess I did a poor job of explaining, so let me try again.

When I click the down arrow at the end of the IE 7 Address Bar window, a
list of previously visitied web sites is displayed in the drop down window,
along with the associated "Favicon" for each site.

Within a day or two, these favicons are replaced by the generic 'e', and I'm
just trying to understand why, since I haven't cleared my cache -- and the
expiration date for these "favicon.ico" files (in my Temporary Internet Files
folder) is NONE.

I'm just trying to understand why, since this is only a problem with
Internet Explorer -- no such problem with Firefox.

NOTE: I solved the problem that you described a long time ago with the
Favorg utility.