I tried to download your demo but unfortunately to no avail - it was not available - see the attached screenshot which I prepared for your reference.
To correctly configure a tooltipified grid you should fulfil the following:
1) The new values in the user control's content controls should be set in the user control's PreRender event.
2) The targets should be added to the RadToolTipManager's TargetControls collection in the grid's OnItemDataBound event.
3) The TargetControls collection should be cleared when the grid is paged and sorted.
4) If you have ajaxified the grid, you should add the tooltip manager to the same settings - e.g put the manager in the same update panel or add it to the same ajax settings of ajax manager where the grid is added.
The basic logic is the same for other databound tooltipified controls with paging and you should simply follow the same corresponding steps in your particular scenario.
A sample demo is available below:
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