To me, all the four examples you provide return a perfectly valid result, or at least exactly the result I would expect. So nothing wrong with them IMHO.
Contrary to the OP's question, which really appears to be displaying an actual bug.
Update: Of course, I meant: all the four examples as originally provided by sundialsvc4 return a perfectly valid result. The last example, as it stand now, does no longer return a valid result, but that example was changed by its author almost 24 hours after I posted my comment above. Fortunately, hippo provided a copy-and-paste of the last example as it was originally posted and as it was when I answered, thus showing that this comment was right at the time.