Weird... I hear people report this all the time, but when I did my cider in september each of 5 fermenters got a couple tablets which I broke but wouldn't say crushed, and they were completely dissolved within a half hour, and bleached out the cider a couple shades. I think it might be a freshness issue. My LHBS does more wine than beer, and they move all that stuff through pretty quick. I wouldn't worry about it and would just pitch your yeast. Unless you added a bunch of them I can't see it interfering with your fermentation. Once cider gets yeasted it takes off like a rocket.