Red X in Outlook 2003 When on Dialup Modem

I’m using a laptop with Vista and Outlook 2003. When I am in the office on a dedicated 56K high speed connection I get images in my outlook messages from all companies. If I go home and dial up using Netscape, when I open the same messages I get red “x”s in place of the images. Also, there appears a drop-down bar that states I am being put in the “Internet Zone” instead of “Intranet Zone” since the Intranet Zone is less secure.

I have tried the common solution out there of locating the Outlook temp folder and deleting all the files from it, but I couldn’t locate the folder that was specified in the Registry.

What would cause the loss of the images only when in dial-up mode versus high-speed??