org.springframework.web.servlet.tags.form.TagIdGenerator which is used by tags checkboxes and radiobuttons doesn't filter out [] and double-quotes from id attribute. It breaks html and javascript for map-based properties. Can be fixed like this:
public static String nextId(String name, PageContext pageContext) {
String attributeName = PAGE_CONTEXT_ATTRIBUTE_PREFIX + name;
Integer currentCount = (Integer) pageContext.getAttribute(attributeName);
currentCount = (currentCount != null ? new Integer(currentCount.intValue() + 1) : new Integer(1));
pageContext.setAttribute(attributeName, currentCount);
return (StringUtils.deleteAny(name, "[]\"") + currentCount.intValue());
}