It took me a day's work to figure this out (ICEfaces 1.8.2) - I wish I had come across your info in the first place. The behavior is unexpected indeed: the explicit column id won't be used anywhere in the rendered HTML (for a simple table, at least), the UIColumn's child objects will be provided with an automatically generated id by the framework just fine - but still, omitting to explicitly call setId() on the UIColumn will effectively break the UISeries' saveChild/restoreChild mechanism. Thank you.