This problem affects people using the KDE4 desktop with the “Oxygen” style and a recent version of the LibreOffice suite. (I’m running LibreOffice 3.4.2 on OpenSUSE 11.4) The horizontal scrollbar in Calc just doesn’t work, so if your spreadsheet is wider than your screen you can’t use the scollbar to view the right hand side.
The problem is with the Oxygen widget style. On a host running OpenSUSE 11.4 you can change this by going to:
Applications > Configure Desktop > Application Appearance > Style
Then set “Widget Style” to any style except “Oxygen”. Click Apply.
Problem solved.