This is very important. And it seems there is no way to manage certificates on maemo, which is a shame. So yeah, as jd4200 said, simply delete the certificate on your computer, then copy the cert8.db to /home/user/.mozilla/microb/. Not sure how microb makes usage of OCSP.
Edit: better this http://talk.maemo.org/showpost.php?p...7&postcount=12 and http://talk.maemo.org/showpost.php?p...86&postcount=7

Anyway, it's an OS from October 2010. I bet there much much more security issues, probably even remote :-).