I had the same issue on my 'to-fix' list; if the datasource for the repeat had at least one document in it already, it worked fine to add more, but the first one wouldn't show up until I did a full reload of the page. Following Paul's suggestion of refreshing the view I was accessing for my datasource worked for me. It is just odd that the refresh is required when there were previously no documents, but was not necessary if there had been some. As an aside, I was using view.getAllEntriesByKey() to feed my repeat, not the whole view.
Rich