environment: myFaces 1.1.5 and a4j 1.1.1
I can't close a wizard if there is invalid input in any field.

My Wizard page contains an inputText field with a nested <f:validateLongRange minimum="0"/> to allow only numbers > 0.
At the bottom of the page is a a4j:commandButton to close the wizard without any further processing. If I enter "abc" in the text field and click this cancel button then a "conversion error" occurs "Value is not a valid number".

snippet:
<t:inputText id="number"
maxlength="3"
value="#{MyController.myWizard.number}">
<f:validateLongRange minimum="0"/>
<a4j:support event="onchange"
reRender="bw_p2_of1"
oncomplete="enableSubmit();showProgressBar(false);"
id="aChangeNumber"
actionListener="#{MyController.dummyListener}"/>
</t:inputText>

<a4j:region id="aRegionCloseATBWp2 renderRegionOnly="false">
<a4j:commandButton id="closeATBatchWizard_p2"
ajaxSingle="true"
immediate="true"
action="closeATBatchWizard"
reRender="wizard,a4jATBatchWizard"
oncomplete="enableSubmit();showProgressBar(false);">
</a4j:commandButton>

I tried:
- ajaxSingle="true" and immediate="true"
- ajaxSingle="true"
- immediate="true"
all without success.

How can I close a wizard via a4j in this case without any validation or conversion errors ?