Thanks for the replies.
Sorted. When I went to the Adobe downloads site, I could download the file.
But, the auto update prompt this morning said 3.6, but became 3.5 when I clicked on it.
Also, while 3.5 was still installed, if I went to look for updates, it prompted an update to 3.5 too. So, there was definitely something amiss with what I was being offered automatically.
But, as I say, no problem at the Adobe site.