[Kaosvf]

Please do a Search in Templates for ".pagination span.selected a" It should come up in the template vbulletin.css. This is the code in there:

.pagination span.selected a {
background: {vb:stylevar pagination_current_background};
color: {vb:stylevar pagination_current_color};
border: {vb:stylevar pagination_current_border};
height: {vb:math {vb:stylevar pagination_font.fontSize}{vb:stylevar pagination_font.units}*{vb:stylevar line_height}};
font-weight:bold;
padding: 2px 4px;
margin-{vb:stylevar left}: 1px;
}

Is that in your css template vbulletin.css ? If not, you may have to add it, although I would recommend either reverting the template (in which case you will lose all changes you have made to it) or update it (click View History > Compare and see what has changed and modify your template appropriately).