How do I transition between pages using something other than a white screen

You can't. It's a function of your browser. You site pages are loading very slowly in Safari, more so than with Firefrox or Google Chrome. Safari displays its default white background until it can read the page's html code, identify the background color and apply it. Once the page has been opened one and cached then the delay is much less and the white background may not be seen again until the cache is cleared.

OT

Roddy has some tips at his iWeb for Musicians site: How to get your iWeb Site to load in Internet Explorer.

Using an optimizing application like Web Site Maestro can greatly reduce the "weight" of a site's pages to facilitate faster loading. I use it event thought my sites are geared for Mac users and it greatly reduces the size of the files in the site.

This tutorial is how to use Web Site Maestro with MMe: #12 - Using Web Site Maestro to Publish to MobileMe. However, it applies to using a 3rd party server. The only difference would be the ftp address you enter in WSM for uploading to your server.

Picture 3 in item 3 shows you what to enter in the fields.