Apart from changing your blog title, did you do any other changes, in Blogger or in Feedburner ?
The people that are saying they're not receiving anything ;
Anything in common with them , such as the email provider they are using ?
Have they all checked their spam/junk folders, and doublechecked their filters ?
It's a small miracle that both Feedburner feeds are up to date, what with
dangerously close to the 1024 KiB limit.
You should change your Original Feed (on both Feedburner feeds) to
Also, stop copy&pasting from Word directly into Blogger and remove
the junk Word formatting from your existing posts.