The Seam "ui" example's selectItems page was not lining up labels with their counterparts properly, nor applying CSS style properly. This was also observed with ICEfaces' seam-gen, where it's pretty typical to have an s:decorate around an s:label and some input component. The problem was that the html that ICEfaces was producing was wrong, and observably different than stock seam output.

Example source xml:

<s:label styleClass="label #{invalid?'errors':''}">
    First Name
    <s:span styleClass="required" rendered="#{required}">*</s:span>
</s:label>

Expected (summarised) html output:

<label for="firstName" class="name ">
firstName<span class="required">*</span>
</label>

ICEfaces (summarised) html output:

<label for="firstName" class="name "
</label>
firstName<span class="required">*</span>

Basically the problem was that the children of s:label were being rendered as peers. s:label extends h:outputLabel, and we supplant its default rendering our own D2D renderer. This was confirmed by replacing s:label with h:outputLabel and observing the same incorrect html output.