There is an issue where I try to update my addons (Fresh install of ArkiveUI) and WoW on Vista64 machine. Curse, instead of installing/updating my addons...it's deleting them???? I had the addons folder opened during the update and saw the folders disappear. WTH is with that?
Normally when installing an addon you delete the existing folder & then extract the new one into it's place. The zip file that you download ( or the one the client downloads) contains the parent folder that everything goes inside of.
Now if it's not reinstalling the same addon when you go to update, then either there was a name change or it's identified the addon as something else.