Tweaking a Form for different browser

I didn't create this form, I'm using an open source php script
and trying to work with it as best I can.

It looks good in IE7 and IE6, except for the CITY field. It looks good in IE7, but it is too far left in IE6. When I adjust it for IE6, it looks worse in IE7. Why this field? It's maddening. Any suggestion would be appreciated. Thanks

<div class="signup-right">
    <br />
    <h1 style="border-bottom: 1px solid #800000;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[var.lang_register_today]!</h1>
    <form action="join.php" method="post" name="capform" class="FormGeneric" onSubmit="return capCheck(this);">
    <div>
      <div style="margin-left:30px; display:inline;float:left;">
        <b>[var.lang_first_name]:</b>
      </div>
      <div style="margin-right:65px; display:inline;float:right;">
        <input type="text" name="first_name" size="26" value="[var.first_name]" />
      </div>
    </div>
    <br />
    <br />

    <div>
      <div style="margin-left:30px; display:inline;float:left;">
       <b>[var.lang_last_name]:</b>
      </div>
      <div style="margin-right:65px; display:inline;float:right;">
        <input type="text" name="last_name" size="26" value="[var.last_name]" />
      </div>
    </div>
    <br />
    <br />
<div>
      <div style="margin-left:30px; display:inline;float:left;">
        <b>Address 1:</b>
      </div>
      <div style="margin-right:65px; display:inline;float:right;">
        <input type="text" name="Address_1" size="26" value="[var.Address_1]" />
      </div>
    </div>
    <br />
    <br />
    <div>
	      <div style="margin-left:30px;display:inline; float:left;">
	        <b>Address 2:</b>
	      </div>
	      <div style="margin-right:65px; display:inline;float:right;">
	        <input type="text" name="Address_2" size="26" value="[var.Address_2]" />
	      </div>
	    </div>
	    <br />
    <br />

        <div>
		      <div style="margin-left:30px; display:inline;float:left;">
		        <b>City:</b>
		      </div>
		      <div style="margin-right:32px; float:right;">
		        <input type="text" name="City" size="24" value="[var.City]" />
		      </div>
		    </div>
		    <br />
    <br />


            <div>
			      <div style="margin-left:30px; display:inline;float:left;">
			        <b>State/Province:</b>
			      </div>
			      <div style="margin-right:65px; display:inline;float:right;">
			        <input type="text" name="State" size="26" value="[var.State]" />
			      </div>
			    </div>
			    <br />
    <br />


      <div>
        <div style="margin-left:30px;display:inline; float:left;">
          <b>Zip Code/Mail Code:</b>
        </div>
        <div style="margin-right:65px; display:inline;float:right;">
          <input type="text" name="zip_code" size="22" maxlength="5" value="[var.zip_code]" />
        </div>
      </div>
      <br />
      <br />

Code (markup):