This is what I wrote in the morning - it disappeared then and it's likely to disappear again, but this is the only way to find out whether Blogger has fixed the problem...
I've no idea what's wrong with Blogger. I posted two entries between midnight and 1 am, and they disappeared; I found them through RSS, reposted them - and they vanished again; comments do get sent to my email address, but they don't show on the page.
Now, the craziest part of it is this: to post this entry, I'll have to do the Word Verification routine. Here's why:
Blogger's spam-prevention robots have detected that your blog has characteristics of a spam blog. (What's a spam blog?) Since you're an actual person reading this, your blog is probably not a spam blog. Automated spam detection is inherently fuzzy, and we sincerely apologize for this false positive.
Before we can turn off mandatory word verification on your posts we'll need to have a human review your blog and verify that it is not a spam blog. Please fill out the form below to get a review.
Okay, so I've found the explanation for the disappearing posts and comments problem - it's here, in a thread on Blogger Support Group. Not an explanation, really, but at least I know that I'm not the only person this is happening to.
As for my blog being a spam blog - maybe someone has used a "flagging" option in the upper right corner of the blog and notified Blogger "about objectionable content"? Accidentally. Or deliberately. I'll have to find out.
I'll try to repost my two earlier, disappeared, posts later. Hope it'll work.
And no, it didn't work for those two posts from a night ago...
I'm still on their spam blog watch list, though. Funny, huh?