We updated the library with the fix for the ScrollbarValue property, and you should be able to download it using your original download link. Make sure the old qcspcchartgwt folder (Quinn-Curtis\GWTJavascript\QCSPCChartGWTWar\qcspcchartgwt) is deleted before you unzip and overwrite or copy over the new one. The contents of that folder are what that you need to change to bring in the new library.
Set the value using the following script:
"Scrollbar": {
"EnableScrollBar": true,
"ScrollbarPosition": "SCROLLBAR_POSITION_UNCHANGED",
"ScrollbarValue": 5
}
Let us know the results. Thank you for reporting this bug.