[GXT 3.0.4] UiBinder FieldSet in HorizLayoutCont with width -1 has wrong width IE7

[info@csamed.it]

<ui:with type="com.sencha.gxt.widget.core.client.container.HorizontalLayoutContainer.HorizontalLayoutData" field="step1MainHorizontalConfig">
<ui:attributes width="-1" height="190" margins="{normalMargin}" />
</ui:with>

<container:HorizontalLayoutContainer>
<container:child layoutData="{step1MainHorizontalConfig}">
<form:FieldSet headingText="{i18nC.state}" collapsible="false" resize="false">

etc etc

in IE7, when i open a panel with such layout my fieldset renders with, seems, a default width of say 50px.
Only way to have it right is to set through "step1MainHorizontalConfig" a fixed width.

Kind regards,

Marcello.

[info@csamed.it]

I cannot try myself but i suspect this can be an issue on IE6 also. Thanks.