I posted two days ago that Google Reader is displaying some blog posts with the HTML code showing, and that I could not find any way to inform Google Reader or find out from them about this fact. Later that night, someone from the Google Reader team left a comment to my post, pointing me to a GR forum and a possible explanation. According to the GR forum, the problem is with atom feeds from typepad blogs-- there is a generic corruption or error in the code. The recommended solution is to switch the feeds from atom to rss. I tried this with a couple but no better. The other recommended solution is to inform Typepad, as the problem seems limited to this blogging platform. I therefore opened a Typepad help ticket last night, pasting in the GR forum post explaning the coding problem. Today I received an email from Colleen of Typepad saying they are working on the problem and hope to have it fixed soon.
Thank you to Google Reader (and my apologies for being short with you in my earlier post, but I had spent some time failing to find any way to solve the problem) and thank you to Typepad for your prompt response.