I have a few coins that are smaller than the holes and I usually just cut up a 2x2 in thin pieces and make shims to place around the coin to hold them in place. Dansco has been asked about this and they said because each series has different sizes through out the years and they used the biggest size possible for the dates that was supposed to go in that slot. The mint didn't mint some coins with a collar so the sizes were not always the same. I have hward dansco will send some shims to you also if you ask but I am not sure about that because I just made my own. My large cents are not the ones I had a problem with though, I had most of the problem with the smaller gold coins and the 20¢ piece if I remember correctly