i test the checker für 6 icons, i become the answer,:
"My best date was at 2011-07-02 when I found 7 different cache sizes"
.... and the List of them.
Have you test the Checker ? What tell the Checker if you have only 4 or 5 found Types/a Day ?
... You did not fullfill the Task, you only have 4 Types a day and then you get the List with the found types ?
So if the List include 5 Types/ Founds, you have the answer / check for your 5 Types Challenge.