Norton's telling users to run LiveUpdate to receive their fix for this issue.
We see many users have been experiencing issues downloading the tools patch this morning (which would then allow them to download 4.1), however SONAR is flagging it and blocking the download.
Essentially, you'll want to temporarily disable SONAR to patch, then re-enable it.
SONAR doesn't work off of known malware, etc, but instead works off of the number of users who have downloaded the file.
The patch just came out, SONAR recognizes that few people (with Norton) have downloaded the file, so it blocks it.
I'm running the corporate edition of what you're running, and nothing flagged for me, installed nicely with no blips.
It is safe. I guarantee it. :)