Change this line in the template modification:
Code:
<if condition="$vboptions[referrers_onoff]">
to this
Code:
<if condition="$vboptions[referrers_onoff] AND is_member_of($bbuserinfo, 1,2,3)">
Change 1,2,3 to whatever usergroups you want to allow to see the list.
Your forum is down but I have a suspicion it's because I forgot to account for URLs with hypens.

Might be a setting issue though, can you tell me exactly what you have entered in
AdminCP > vBulletin Options> Site URL > Forum URL.
Blocked words work by blocking entries from being made in the first place, NOT from them being added if they're already there. So once the domain containing the keywords is removed, it won't be added again but it will continue to count up until then. This was done to keep the recording of referrers very quick. I'm looking to add an inline-delete for the next version to make this more usable.