I am not certain exactly what you are doing or seeing, but perhaps this blog article will help explain how annotative content works in 2008:
http://architects-desktop.blogspot.com/2007/04/annotative-tags-with-leaders-in-aca.html
Executive Summary: A tag with a leader will, if both the leader's dimension style and the tag's view block are set to be annotative, rescale themselves as the drawing scale is changed. The endpoints selected for the leader will not, however, shift to stay "connected" with the same relative point on the tag. You can, however, manually edit the leader for each scale at which you need to show it, and the manual edits will be "remembered" independently for each scale.
Multileaders allow the ability of one leader to point to multiple locations, not to the ability for one leader to have multiple scales. Both leaders and multileaders can be made from an annotative dimension style.
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David Koch
Autodesk Discussion Group Facilitator
Using ADT 2004 at work; access to 2005, 2006, 2007 & 2008 at home