They always are, nothing wrong with them. Amazing how something with the texture of concrete before its cooked turns into something quite soft and mushy after cooking. Try a very sharp breadknife, that's what I always use, although there have been times when i've wished for a pneumatic drill...

Sturdy, mid-size kitchen knife, with a newly sharpened edge, and maybe dragoon someone with strong wrists! Nicking the skin with a sharp fork or ice pick seems to help, too. Those hard shells are what helps them keep nearly to spring.