OK, here si what we just did after going to your account:
1. On My Account clicked the EDIT link for editing the new site (you seem to have CREATED this site numerous times???)
2. On the edit page, under Add & Edit Your Page's Content we selected the edit link for the main page.
3. This opened a new window, to edit that specific content area. We clicked in the edit window, went to the end of the xisting text, pressed return a couple times and entered the word TESTING
4. We clicked PUBLISH. I fyou don't click publish nothng is ever seaved.
5. AFTER clicking publish we tried two things:
A. the preview page link on the newly opened edit page (where we entered the word TESTING)
B. The preview link on the main site editing page.
Both show the word TESTING in the main page content area now.
Try that and see how it goes.