Weird AdSense Problem

I am having a (to me) very odd Google AdSense problem.

For starters, my URL is funjoelsisrael.com

I have two blocks of AdSense ads — one that is horizontal, text-only, between each blog post, and one that is in a Textbox widget in the sidebar. Both had been working perfectly fine for a while.

Now, however, the one in the sidebar seems to have disappeared, leaving a blank space where it was. Making this particularly peculiar is the fact that it only happens on the home page, but in any other page of the blog, the ad block is there, even though the sidebar is generated from the same place on all pages.

The issue is not that Google isn’t finding any appropriate ads, because my settings are set up to show a public service ad in those circumstances.

Anyone have any thoughts?

Thanks in advance!

Joel