Error 500 when adding second page

Since testing this on a local server and then building it again from scratch on a live Apache server, I was cruising along fine until I tried to add a second page to my site.
First, I created a second template similar to the first but with different graphics.

Then, I created a simple one word document and told it to use this new templage.

Now I get a "500 server error" and am told to check my server logs. When I do I see:

"Request exceeded the limit of 10 internal redirects due to probable configuration error."

I'm using MODx Revolution 2.1.3
Apache on Red Hat Linux 5, Linux 2.6
PHP 5.2.17

Okay, I found something, but I don't know enough to know what's exactly "right or wrong" about it. When I turn off RewriteBase in my .htaccess file the error goes away and my site comes back.

I'm told the RewriteBase has something to do with friendly URL's working, and I did what the comments said and set it to the MODx directory. It worked for page 1, but as soon as I added a second page, it died.

Weird!

Even without it, the friendly URL still seems to work.

Weirder!