rowcolumn scrolling problem

Hi,

Can someone tell me how to fix this problem?

When scrolling horizontally, the label or button in the rowcolumn will disappear sometimes, seems at certain position.

What I did for the rowcolumn when scrolling the scroll bar is:

XtVaSetValues ( RC, XmNleftOffset, -(cb->value), NULL);

cb is scroll bar call back.

Thanks.