Hi Annie I though it may have been Mealy bug but the edges of the leaves put me off,
Maybe sunburn or a mineral deficiency do you know if Lime has been added lately.
Mineral Deficiencies
Have a read anyway you may find the answer if no one else knows....Cheers...MM.

Here is a link that might be useful: Cycads Pest and diseases

Hi, MM, I meant to add that in the centre of the thing looks like sawdust?
We haven't had that much sun...not to cause that damage, anyway. I had thought of that but the leaves below the damage are fine.
Thanks for that site. I'll have a read thru it and see.
I might ask Alison or Ian Wintle to have a look at the photo...maybe they would have some ideas.
thanks,
Annie

Hi Annie, no expert on these. But unless your neighbour has particularly bad-draining soil and they have been deluged in the recent rain, I would suspect scale.
Please go have a look along the stems and fronds and particularly under. Green scale is barely detectable sometimes, run your fingernail along and see if you expose orange juice, that's them, live ones.
Then post back. I think I remember someone else in Bris mentioning this was a problem and will find links if you agree that's it.