.x-grid-cell-checkcolumn .x-grid-cell-inner {
    padding-top: 4px;
    padding-bottom: 2px;
    line-height: 14px;
}
.x-grid-with-row-lines .x-grid-cell-checkcolumn .x-grid-cell-inner {
    padding-top: 3px;
}

.x-grid-checkheader {
    width: 13px;
    height: 13px;
    background-image: url('../resources/ext-theme-classic/images/form/checkbox.gif');   
    background-repeat: no-repeat;
    background-color: transparent;
    overflow: hidden;
    padding: 0;
    border: 0;
    display: block;
    margin: auto;
}

.x-grid-checkheader-checked {
    background-position: 0 -13px;
}

.x-grid-checkheader-disabled {
    background-position: -39px 0;
}

.x-grid-checkheader-checked-disabled {
    background-position: -39px -13px;
 
}

.x-grid-checkheader-editor .x-form-cb-wrap {
    text-align: center;
}