Brakes Ford KA?

Having just renewed the discs and pads on my ford KA, I found that on retightening the guide pins, [caliper bolts], they did'nt seat home as far as the old ones and seemed to come up against the back of the pads leaving a gap between the caliper and the mount. they're tightened right up and I've test driven it ok, I was just wondering if anyone could tell me are they safe!