Permit free scrolling in xceed grid vb.net

I use a GridControl in Xceed.Grid in vb.net.

In my grid, the rows' height are specified by some timespan information.

I would like to permit the user to scroll into this grid, but the problem is that every time you scroll once in the grid, you scroll until the beginning of the next row.

I would like to know if it's possible to scroll a definite height in the grid when you scroll with your mouse.

I search in the properties of the gridcontrol but I didn't manage to find any property that handle this problem.