My guess is, because I don't know what your css and/or code looks, that the ScrollPanel doesn't have a fixed height, and expands with the content in height. The VerticalSplitPanel probably has a fixed height (or due to its context gets a fixed height), and gets the scrollbar. In such a case, setting a height on the ScollBar will probably fix it.
Hilbrand
2009-07-22 10:14:29