I can confirm that those accordions on the pricing and guides pages are not working in FF for me. Sorry, @luxlogica. Never meant to pile on with complaints.
@tim, thank you for your feedback - and don't feel sorry: it's very important for me to get feedback like this, indeed, so I can correct problems that I may not have seen!
If I remember correctly, you had also found problems with the accordions in the Android browser. I think I must be doing something different with the accordions in this site, which is causing these issues - I'll have to have a closer look and compare with previous work. Unfortunately, right now I'm a bit snowed under with work, and this being my own site, means it'll have to wait...
Once again, thank you for the feedback. Once I've made some changes, I might have to ask you to please check it again for me, ok?