People Picker not removing previous data

Question

I am trying to implement People Picker in my aspx page. I have added this tag into my aspx page :

<SP:PeopleEditor AllowEmpty="False" ValidatorEnabled="True" id="Picker" BorderWidth="0px" MaximumHeight="20" runat="server" MultiSelect="False" ShowCreateButtonInActiveDirectoryAccountCreationMode="true" SelectionSet="User" />

as well as register it using below :

<%@ Register Tagprefix="SP" Namespace="Microsoft.SharePoint.WebControls" Assembly="Microsoft.SharePoint, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>

Now, when I input value and resolve it, it's working fine. When I remove the resolved user from people editor using backspace it is shown as removed. But, when I input another user name/ID and try to resolve it, it shows HTML like below with message "You are only allowed to enter one item." in IE8 and IE9 (it works fine in IE7):

<SPAN id=spanXYZ\test_a class=ms-entity-resolved title=XYZ\test_a tabIndex=-1 contentEditable=false>
  <DIV style="DISPLAY: none" id=divEntityData description="XYZ\test_a" isresolved="True" displaytext="Test Admin" key="XYZ\test_a">
    <DIV data='
      <ArrayOfDictionaryEntry xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
        <DictionaryEntry>
          <Key xsi:type="xsd:string">DisplayName</Key>
          <Value xsi:type="xsd:string">Test Admin</Value>
        </DictionaryEntry>
        <DictionaryEntry>
          <Key xsi:type="xsd:string">Email</Key>
          <Value xsi:type="xsd:string">tes_a@axyz.com</Value>
        </DictionaryEntry>
        <DictionaryEntry>
          <Key xsi:type="xsd:string">SPUserID</Key>
          <Value xsi:type="xsd:string">666</Value>
        </DictionaryEntry>
        <DictionaryEntry>
          <Key xsi:type="xsd:string">PrincipalType</Key>
          <Value xsi:type="xsd:string">User</Value>
        </DictionaryEntry>
      </ArrayOfDictionaryEntry>'
    >
    </DIV>
  </DIV>
new test
</SPAN>

Please let me know, what needs to be done for the same.