qscrollbar styling

[20khz]

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

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

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

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

can somebody help me?