I had a new shower and screen over the bath fitted in my holiday cottage last year. I specifically asked for a fixed screen, because we had a moveable one at home once and we always had leaks. The plumber turned up with a moveable screen, and assured me that it wouldn't leak. Sure enough, as soon as it was fitted it started leaking. Of course, having lots of people use it doesn't help - if it was just me and DH, we would know to 'be careful'. Anyway, I got the plumber back and asked him to seal it using the bath sealant stuff you can buy. He did this and, although I had to patch it up once, it has held for a year now with no leaks.