I'm pleased to say I've sorted it out. The problem was caused by me changing the footer height from 30px to 0 to reduce the height of the white space above the footer. As I said, it only showed as problem on Safari.

Sorry to waste the time of the forum.

Chris

I did the same thing, so I'm so glad that you posted. Ten seconds later and the problem was solved.

The solution for me was in:
Page/Post Stylings > Post Container > add 30px in footer in the margin section