Vertical Scrollbar Visibility
So, this is something very basic i learned today. The scrollbar in silverlight appears only when the length of the container is predefined and not depended on its parent container.
For example, if you set the grid row height in which you have placed you textbox to "AUTO", you will never be able to see/activate the scrollbar. Simply because the textbox assumes that you have set the parent grid in a manner that will keep the size in check. Instead of activating the Scrollbar in the container, in this case the text box, it will simply stretch the textbox beyond the parent container boundary.
Another instance of this is when you set the Gird.RowSpan or Grid.ColumnSpan for the textbox. Again in can never decide when to activate it, as its height is dependent on its parent grid. And the grid itself will keep expanding as the textbox expands as it keeps getting filled with more and more data.
This can be avoided if you set the Grid height to "*", in which case it should be able to activate the scroll, because for some reason, with "*" it can pre-compute the size somehow.
Having said that, the star(*) will fail to work in case of the Row and Column Spans. Simply because the issue is not with the height, but with the extent of the textbox which is ultimately decided by the parent grid.
The best solution is to try and maintain fixed size textboxes for activating the Scrolls. It only makes sense, right? Otherwise why would you need a scroll, if you do not find it important enough to fix a length?