There's an annoying quirk when uploading via FTP do to with how/where it picks up the filename and target for the upload.
Scenario:
I have two web site projects, open #1 and do some editing, then open #2 and do some editing on say C:\Website2\shop\cart.html
Whilst editing in #2 I realise I need to make a change to a file in project #1. So I go File -> Recent Files and select the file to edit, say C:\Website1\index.html
When I finish editing I do a Ctrl-S to Save it then hit F4 to upload it.
What happens now is it uploads C:\Website2\shop\cart.html because that's the file highlighted in the "Local Disk" tree on the left. Until you figure this out, you keep saving and FTPing and no changes are visible !
What I believe it should obviously do is FTP the file you are editing as it knows what it is based on the ability to "save" it to the correct place.
An "FTP Log" window or text file would be useful as well

Thanks