Law Profs, Defamation, and Insurance Coverage

On LawProf, Andrew Beckerman-Rodau (Suffolk) asked the following question:

I was just denied a personal umbrella liability insurance policy
because I am a professor who has published. According to the insurance
company anyone who has published presents a risk of potential liability
for defamation. Has anyone else ever run into this problem?

(Thanks to Rick Peltz (Arkansas-Little Rock) for passing it on.)  I obtained an umbrella policy about a year ago and publishing was not an issue.  However, I have since questioned whether I would be covered under any of my personal insurance policies for blogging.  The answer was no, so I made sure I was covered under the university's policy.  Has anyone else had experience on either issue?

--CJR