XUL box for %1$S element contained an inline %2$S child, forcing all its children to be wrapped in a block.  This can often be fixed by replacing “display: -moz-inline-box” with “display: -moz-inline-box; display: inline-block”.
Roedd y blwch XUL ar gyfer elfen %1$S yn cynnwys plentyn mewn-lein %2$S, gan orfodi'r holl blant i'w amlapio mewn bloc. Mae modd trwsio hyn drwy newid  "display: -moz-inline-box" gyda "display: -moz-inline-box; display: inline-block".