Property with subsidence, problem getting a mortgage

The day started off fairly exciting as a client found a house they liked the look off and phoned up to apply for a mortgage and to view it. It turns out though that the house (two-bedroom terrace) is cheap because it had a subsidence problem (which is all better now) but which will mean it could be a problem for them to get a mortgage on it. I'm not sure i'd want it if its going to slide down a hill, but then I won't be living in it!

The estate agent has sent them the details and that of another (three bed town house) just in case.