vertical scrolling changing the style of the data in the cell

Hello,
I had a activewidgets grid in one of my pages and the data in the grid is displayed according to parent child relationship. In my application the parent is Entity and the children are accounts. when I display the data in the grid, I want the ROW headers for the entities should be bold and the ROW headers for accounts should be hyperlinks. On the initial load of the page the data is displyed as expected. When i try to scroll down and come to the top of the grid the ROW header of the entity row is turning into hyperlink.

This is happening when the number of rows in the grid is more than 60.
I request you people to help me out in solving this problem.

Thanks,
Ravi.