PROBLEM not able to switch between page templates

[sgvri]

Hi. I'm new to this CMS and it looks great. I've installed it twice on two servers and I've installed a few extra themes.

In all cases, I'm having difficulty changing the templates for a specific page. When I use the admin page to select a different template and then view the page, it always continues to look like the homepage (default) template no matter what I try. I tried flushing the cache as well. I added HTML comments into the default template.php file to differentiate it from wide.php and others so I can confirm that the default template is always being displayed/used. Switching between themes seems to show the same problem as well. Any ideas on how I can solve this problem?

Thanks in advance!