Error when closing pipe to /usr/lib/sendmail

While trying to submit a comment for CORE-3639 in Bugzilla, I received the following message:

"There was an error sending mail from 'ReactOS.Bugzilla' to 'gedmurphy@reactos.org':error when closing pipe to /usr/lib/sendmail: "

After going back to the previous page and re-submitting, I got another message:

"Someone else has made changes to CORE-3639 at the same time you were trying to."

The message shown was my own, so it looks like my actual comment was sumbitted okay.

In case it helps, I was using Firefox 3.1 Beta 2 under Windows Server 2008.