This is indeed a very common problem, if you get the whole wiper system changed the problem will return within 30000 or so.
I have learnt to live with them and they do improve after being used constantly on full wipe, but it does take about an hour.
You can get bosch wiper arms and blades which are much better than the standard fitment ones which wear out and fall of the car when you need them most. Also the bosch ones don't hit the bonnet.
Try Alfa Aid who are resonable close to you on 01628 788887