Posts And Sidebar Changes Appearing Then Disappearing

I have two blogs (http://www.amynelsonmile.net/amyblog/ and http://www.amynelsonmile.net/booksblog/).

For the last few days I’ve been having trouble with both blogs–posts that I have put up in this time period periodically vanish, then reappear.

Sometimes it’s just the current day’s post that vanishes; sometimes it’s two or three days worth of posts.

When the post is gone from the main page it’s still visible in the admin/manage/posts section, in the categories section, and the archives section.

Also, when posts are gone, the changes I’ve made to the sidebar are no longer visible–but when I check in my theme editor the changes are still there.

I’ve recently moved my website from one host to another, and in the process I had to move my blogs over.

That’s when my troubles started, although I don’t know if that’s the reason for the troubles.

I’ve checked in the support forums, and I don’t see anything there that I haven’t tried or that might apply. I’ve cleared my cache, and I haven’t future-dated the posts (in fact, the posts often show up fine when I first post them, and then 2 or 3 hours later they vanish).

The only plug-ins I have are Akismet and Scott Merrill’s WordPress Database Backup, both of which I’ve been using for months with no problem.

I tried publishing a test post (with just the headline “test” and the text “test”). I saved it as a draft and tried looking at the main site from the admin section.

From the admin section, the test post and all my missing posts show up fine. When I open another tab in Firefox and look at my blog from it, though, all the missing posts are still gone, and the test post doesn’t show up either. Then, 15 minutes later, everything shows up fine everywhere: the test post, the missing posts, the changes to the sidebar.

Sometimes, for a couple of days, everything works fine. Also, usually when the posts vanish they re-appear within an hour. Obviously, though, I don’t want it happening at all.

Any help anyone can suggest would be very much appreciated.