Sounds to me like it's dry. Possible? If it's up against the house the footings will provide very good drainage, and therefore, potential dryness.

Yes thats a good point worthy1 has made,
But after 10 years and only now your having problems makes me wonder has anything around the outside of the house change, ie something beenput up near to the house walls such as a fence or a tree thats grown so large that its put a stop to rain water etc getting to the creeper ?

I had a friend who put one of those roller covers over his patio table area but forgot about his potted plants all along the house kitchen wall and infact starved these plants of natural rain water and as he'd always had pots infront of the wall and never really neede to water the geraniums he didnt think about it until they started to droop.
just a thought!!!!!!

Is it possibly it could have been exposed to weedkiller spraydrift from somewhere? Its been quite windy lately and it doesn't take much.