It’s April 2019 and I’ve deleted the original post from 2013 except for this photo:
That’s about 3 inches of burr comb under the insulated inner cover (flipped upside down) — several large mounds of comb. This kind of thing can happen when there’s space above the top bars for some reason. The usual reason is that I’ve got a rim on the hive to make space for sugar cakes or protein patties. Leaving the rim on too long while the the bees are in comb-making mode can easily lead to the extra space getting filled with comb. The queen can even lay eggs up there. It’s a mess. Where I live on the eastern most portion of the island of Newfoundland, I try to have the rims removed from my hives before April, but some years the weather is so cold throughout April that there’s no danger of them hopping onto comb-making train. But either way, when there’s extra space in the hive during the warm months of the year for any reason, the bees are likely to fill it with comb of some sort.