CheckBoxField works in Firefox but not in IE6

[Dennis McCarthy]

I have a CheckBoxField in a GridView. Its ReadOnly property is set to True.
When I open my page in IE 6 the column is empty. When I open it in Firefox
1.5 the check boxes are there. Viewing the source in IE 6 shows that the
CheckBoxField control is rendering the following HTML for the first data item:

<td><span disabled="disabled">
<input id="ctl00_mainContent_FormView1_ParticipantGridView_ctl02_ctl00"
type="checkbox"
name="ctl00$mainContent$FormView1$ParticipantGridView$ctl02$ctl00"
checked="checked" disabled="disabled" />
</span></td>

Why isn't IE displaying a checkbox? Is there any way to work around this?

Thanks,
Dennis