Hi
This is just a small CSS problem which can be easily fixed.Open the style.css file of you theme ,find the class ".yafnet a.yafcssbigbutton span" and start playing with its variables.You can increase the width of buttoms.for example:
.yafnet a.yafcssbigbutton span {
background: transparent url('button.gif') no-repeat;
display: block;
line-height: 15px;
padding: 4px 25px 4px 12px;
}
to
.yafnet a.yafcssbigbutton span {
background: transparent url('buttonBackBig.gif') no-repeat;
display: block;
line-height: 15px;
padding: 4px 25px 4px 12px;
width: 100px;
}