This is what Blogger has to say about that:
Blogger now filters comments that are likely spam comments to a Spam Inbox, much like the spam folder in your email. When someone leaves a comment on your blog, it will be reviewed against our spam detector, and comments that are identified as possible spam will be sent to your blog’s Spam Inbox, found at Comments | Spam.
You can help improve our ability to automatically detect spam comments by checking your Spam Inbox and deleting spam comments and marking real comments that may have been flagged as spam as Not Spam.
We are always seeking feedback on how to improve this feature, so please share your feedback with us by clicking on the Report Spam Filtering Issues.
Anybody know how to turn this feature OFF? I couldn't find a way to do that.
If you post a comment and it doesn't show up, don't panic. I will try to check my spam box daily (although honestly, it will most likely be a few times a week) and get your hijacked comments routed correctly. Sorry.