Flash just stops working

I used a macro in a block to create a flash slideshow on my front page. It works great but a day or so later I will pull the site up and it will have stopped- I am left with a blue box with a failure to load statement. When I go into the block and resave the macro it starts to work again. Very strange. How would I address this? I am not sure what is causing it to not work and it seems odd that it works and suddenly stops.