Oversize cursor in Firefox form with textbox background image

I have a webform with background images on the textboxes to give them a nice rounded corner. In Chrome the textboxes work as expected, however, if I view the form in Firefox the cursor appears to size to the height of the image, but the text is a normal size.

Is there a way to override this oversized cursor?

Here is the CSS of the textbox:

    .ed_form_textbox {
    width:319px;
    height:34px;
    margin-bottom:10px;
    padding-left:10px;
    background: transparent url( "/images/textbox.png" ) no-repeat bottom left;
    position:relative;
    border:none;
}

Thanks.

Here's the style information from Firefox Web Developer:

.ed_form_textbox (line 54) {
width: 319px;
height: 34px;
margin-bottom: 10px;
padding-left: 10px;
background-color: transparent;
background-image: url("/images/textbox.png");
background-repeat: no-repeat;
background-attachment: scroll;
background-position: left bottom;
position: relative;
border-top-width: medium;
border-right-width-value: medium;
border-righ开发者_如何转开发t-width-ltr-source: physical;
border-right-width-rtl-source: physical;
border-bottom-width: medium;
border-left-width-value: medium;
border-left-width-ltr-source: physical;
border-left-width-rtl-source: physical;
border-top-style: none;
border-right-style-value: none;
border-right-style-ltr-source: physical;
border-right-style-rtl-source: physical;
border-bottom-style: none;
border-left-style-value: none;
border-left-style-ltr-source: physical;
border-left-style-rtl-source: physical;
border-top-color: -moz-use-text-color;
border-right-color-value: -moz-use-text-color;
border-right-color-ltr-source: physical;
border-right-color-rtl-source: physical;
border-bottom-color: -moz-use-text-color;
border-left-color-value: -moz-use-text-color;
border-left-color-ltr-source: physical;
border-left-color-rtl-source: physical;
font-size: 12px; 
}

.ed_form_textbox:focus (line 65) {
outline-width: medium;
outline-style: none;
outline-color: -moz-use-text-color;
}

You will need to add a font-size: to your class if you want the Caret (text cursor) to be smaller.