when i make a change to the site out of the norm like creating a new forum , it takes about 30 mins to be fully functional on the site , i have ran the tools script but that kills my blogs and i have to reinstall my blogs ,
Try disable XCache and repeat any steps that normally cause your issue, to see if XCache is the issue. Personally I don't think it is since forums are usually fetched from the database, so you may need to take a look over at the mysql side of things.
Its only Admin Side things like renaming a forum or something like that the changes take forever to show up on the board , i never had this issue until i moved to my dedicated server , its like the cache is messed up or something even the New users today thing in admin cp is Wrong
Do you by any chance use a special cache method for your datastore on vBulletin? I've known lag issues with datastore updates if your using the datastore cache and it's not working correctly.
Try disable that by commenting out the line where you use XCache for datastore, then perform actions that would normally cause issues/lag and see if they still occur. If not you found your culprit