Minor Description
Nested selects (N+1 selects) with a 1:N relation work fine as long as the primary result set is mapped to a JavaBean, but when the primary result set is mapped to a Map, iBATIS ignores the javaType of the column with the select attribute and treats it as a simple Object. This is a problem for 1:N cases since it needs to treat the column as a List and use queryForList() instead of queryForObject() to load it.
A small change to com.ibatis.sqlmap.engine.mapping.result.BasicResultMap.java seems to take care of the problem in my case, but there may be a corresponging change required for LazyLoading that I haven't looked into.