For the millionth time, I have thanked my lucky stars that Steve, Husband Extraordinaire, knows everything there is to know about computers. He fixed my problems AND wrote out a detailed summary of what he did. I'm going to post that here as a reference for anyone else who might someday be googling for solutions to the same problem.
Feedburner Fail: Large Photos in Blogger
Last week Feedburner stopped processing feeds on Cindy's blog. Initial investigations didn't turn up much: feedburner's own status blog was silent and a couple of Google searches turned up nothing, so we decided to see if the problem would correct itself in a couple of days. A couple of days came and went and no results, so it became imperative to research the problem in depth and fix it.
Cindy gave me access to her Feedburner account so I could troubleshoot the problem. We found out that if your feed length exceeds 512k bytes, Feedburner decides to stop processing it. OK, though it's quite unfortunate that it fails silently. This was the only hint I could find, so I started poking at the feed to discover what is wrong.
First thing I had to do was disable the feed redirection on Blogger so that I could look directly at what Blogger was giving us. To do this, you must go to the dashboard, select the Settings tab, and then the Site Feed item. Here you'll see the "Post Feed Redirect URL". As you will need to restore this later, copy and paste the URL somewhere safe, then clear the box and press the "Save Settings" button.
Then I was able to go to http://web-sniffer.net/ and entered the feed URL, which for Cindy's blog is http://www.cindyderosier.com/feeds/posts/default. This service then grabs the data, gives some information about it and then displays what it fetched. The shocking thing was looking at the size (displayed in red right above the content) was over 1.6M bytes!
Looking into the content, I noticed a very strange thing: the first post had an embedded image. Usually, image tags look like <img src="http:/...." /> and are only a few tens of characters long. This one was like <img src="base/64%20123aF2432ab...." /> and went on forever. Aha! Here's why the feed became so large and stopped working.
I mentioned this to Cindy and she remembered Blogger's editor acting strangely after inserting the image in question. Of course it was: it was trying to process a huge piece of data in the browser instead of handling a URL like it expects.
This led us to the root cause: Usually Cindy grabs files from her Picasa application, which uploads the photos to Blogger and allows her to enter an image tag URL. Easy and simple and it works. For this one image, she had grabbed it from some site by highlighting the image and copy-and-pasting into the post in Blogger. It put the contents of the file inside the post instead of referencing it.
The fix at this point is obvious, though it was frustrating to do in the Blogger interface as having that image in there really drags things down. I edited the post in question, deleted the offending image and then uploaded the image to Blogger and added the image reference. From this point the Blogger editor started working properly again, and Feedburner would be happy.
After fixing the problem, you have to undo the broken Feedburner redirect that we messed up later. Remember how I said to save that URL? Copy that, and go back to the Blogger Dashboard page with the "Post Feed Redirect URL" box and paste it back. Save your changes and you're back in business.
There was one last thing left to do: poke the feed on Feedburner. Enter your feed address (in this case http://feeds.feedburner.com/CindyDerosierMyCreativeLife ) into Feedburner's ping page and press the "Ping Feedburner" button. Now you're done and your feed will start to show in feed readers, emails will start up again and so on.