It's really annoying and I wonder if anyone else has seen this
behavior.
I compiled mutt from source - presently, on CentOS 5.3,
2.6.18-128.7.1.el5.
Thanks.
I should have mentioned that I tried this, it does not work. Mutt
happily re-creates it and resumes appending copies of the same
certificate each time (after I'm asked whether I want to use it or
not).
FWIW, I have the same issue. Mac OS X Snow Leopard, compiled from source.