qscrollbar styling

hi.
Qt fills scrolling background with non-solid pattern, so that when I
i specify

Code:

---

setStyleSheet(
"QScrollBar:vertical{"
"background: black; "
"margin: 15px 0px 15px 0px; "
"border-width: 1px;"
"border-style: solid;"
"}\n"

---

i see only grey background. I use qt 4.4 rc1 and am compiling 4.4.0 right now.

can somebody help me? ;)