Campo de formulário nao funciona com o Internet Explorer

Galera, eu tenho um campo para calcular o frete. Ele funciona normal com o Google Chrome, Opera e Firefox, menos com o Internet Explorer. Quando vou digitar o CEP os números aparece normal, menos no IE, ao digitar ele fica "invisivel"

Vejam a imagem, para ter uma noção do que estou falando

/applications/core/interface/imageproxy/imageproxy.php?img=http://i.imgur.com/O406SJb.jpg&key=bf1eeee077fa675bfda18611ee6087854fac3f124c64e357ed31f17f2788669d" alt="O406SJb.jpg" />

Abaixo está o css.

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.estimate_postcode { display:none; }

.block-shipping-estimate select,
.block-shipping-estimate input { width: 57%; padding: 15px; border-color: #d3d3d3; height: 10px; position: relative; top: 6px; left: 11px; }
.block-shipping-estimate .radio input { width: 20px; }
.block-shipping-estimate .radio div.input-box { clear:both; }
.block-shipping-estimate .block-content li.item { padding:3px 9px; }
.block-shipping-estimate .block-content li.last { padding-bottom: 7px;}
.block-shipping-estimate .block-content li label { display:none;}
.block-shipping-estimate .block-content li label.required em { float:right; font-style:normal; color:#949393; position:absolute; top:0; right:-8px; }
.block-shipping-estimate .block-content li.odd { background: #eeeeee; position: relative; top: 7px; width: 310px; }
.block-shipping-estimate .block-content li.even { background: transparent; }
.block-shipping-results .block-content { padding: 3px 9px;}
.block-shipping-results .block-content dl dt,
.block-shipping-results .block-content .price { font-weight:bold;}
.block-shipping-results .block-content dl dd { padding: 0px 0px 5px 10px; }

.f-right { position: relative; bottom:35px; left: 193px; font-size: 10px;}

.please-wait { position: relative; bottom: 37px; left: 200px; }

.f-left { position: relative; bottom: 59px; left: 100px; }

.block-title { display:none; }
.block-subtitle { display:none; }

.estimate_postcode { display:none; }

.input.input-text { background-color: #eee; width: 120px; height: 40px; float: left; padding: 5px 15px;}