It seems another aspect of this is that attachments which contain plain text will be displayed by the browser instead of being downloaded.
We used to be able to left-click them and they’d download, but now we have to use right-click > save-as to do that.
To see what I mean, go to this post on our forum and click either of the Sort Tabs.dcf or Sort Tabs.js.txt download links in the first post. Both contain text data (the .dcf is XML and the .js.txt is jscript), and you’ll get a screen full of that instead of a file downloaded if you left-click.
(Checked with both Chrome/Windows and IE/Windows in case it was a browser change.)
Edit: I think the download counts are no longer updating, either. Seems as though the whole of the download processing stuff is not happening when downloads are clicked.