First, I've read many 404 problems here. Most are similar, but none exactly like mine, so here I go.
I changed themes (Easel). My RSS quit working. After working with it several days, I figured I'd start over in Feedburner, so I deleted the feed. It will not validate. However, I noticed that I can subscribe only in Firefox, but not in Chrome, nor Safari, nor on any of my mobile devices.
I deactivated the Feedburner plugin. Still no success.
I'm sure it's a simple solution. Thanks in advance for your help.