My sims never die from old age. They're Immortal.

My sims family, consisted of a couple who's married daughter lives with them.  They older couple got an alert saying, they would die any day now and to get there things in order.  Since then the younger couple has had a baby. 

The baby is now an adult and both original couples are on there last legs, but they never actually die.  they're stuck immortal OAP's.

Anyone got any solutions or experienced the same.  I got the latest update today 22/10/14, but it still hasn't fixed it. 

I mean...I don't wanna sound cold, but they need to bugger off, so I have room to expand the family! 🙂