error using Date in WebGrid

Completing the tutorial I have converted my viewMain to use a WebGrid. When I add a Date field to it, it blows up trying to autoconvert the Date (WebFormElement>>autoConvertToString:) and calling a method called #shorterPrintSloString which is only implemented in a Class called SpDate in the Sport-Times package.

I can fix this by changing the aspect to a method that returns a String instead of Date, but I thought you might want to know about this potential bug.

My viewMain before I change the aspect:

viewMain
        | e entryList |
        e := WebElement new.
        e addTextH1: 'Uwali Contest Site'.
        entryList := WebGrid new.
        entryList columnNames: #('' 'Title' 'Category' 'Start ' 'Description' );
                 setNumbering;
                 columnFilters: #(nil true true true nil );
                 sortOn: 2;
                 collection: self observee contests;
                 columnAspects: #(nil #title #categoryTitle #startDate #shortDescription );
               
                column: 2
                addBlock: [:each | WebElement new addLinkTo: each text: each title].
        e add: entryList.
        e addBreak.
        e
                addLinkTo: self
                text: 'Add a new Contest'
                view: #add.
        self pageFrameWith: e title: 'Contest Site'


Thanks
Leon