I found that sizing the Deck to match the contents can prevent your users from getting a "blank" card.
I have a report that displays multiple cards, and on each card is a different set of outliers in a list report.
There is a button bar above the deck to select the desired card.
When navigating between cards, sometimes the card appears to come up blank.
If the user mouses over the card or clicks on the button again, the data appears.
I finally realized that the block and list on the card had their sizes defined, while the deck size was not defined.
As soon as I defined the deck size to the approximate content size of everything on the card, the problem was solved.