Custom Template Disables my Cart

I just followed the tutorial "How do I Create a New Custom Template?" to the point that it tells me to go to my admin. I can no longer get to my admin once I upload my CUSTOM folder, nor will my index.php load. This is my second attempt. I completely uninstalled Zen-Cart, deleted all the files, the first time it happened, because I thought I might have made a mistake, then reloaded, re-installed, made absolutely to follow all the instructions to the letter the second time. I haven't even customized the template yet. The only thing I have done is make a duplicate and upload it to a CUSTOM folder.

Has anyone else experienced this? Can someone help? I haven't done anything else to it; it is a new install of 1.3.9d.

I can only assume you're uploading the custom folders to the wrong place. Nothing you upload to the cart file area would disable your admin.

Where exactly are you uploading these folders/files ?

Actually, I found out later that there was a server problem. Anything/everything ending in .php was timing out. I went to my server and changed to PHP 4 (from PHP 5), and everything worked again. How it just happened to catch me (both times!) right after I made those changes was oddly coincidental.