Hi Andy,
You appear to be one fo the very few customers that have expereinced this issue. Resolution or really workaround was to reset the ev client.
It appears that it was asthetic, rather than caused any issues, but if you are willing to persue this and capture information for Symantec as it appears very difficult to reproduce,
I would recommned that you log a case. In the past it appears customers were too happy to ignore it or work around it and always difficult then if Symantec cannot get to the bottom of it by reproducing.
Sorry cannot give you a quick answer.