I tried referring to 2 members by placing the '@' symbol before their names in a comment. I removed one of the '@' symbols and was able to post the comment.
I then clicked on 'Edit Comment' and tried adding the '@' symbol, but this time around I got an error message that said "You may only edit a comment every 5 seconds".
I think this error message shouldn't have been shown and is incorrect since this was my first edit of the comment.
Edit: This error appears even if the comment is new. To summarize: if I post a comment referring to two members, I get the error as shown here.
I'm running Chrome 14.0.xxx.xxx on Ubuntu 11.04.