PROBLEM SOLVED - but I will leave this post in case it helps others. It seems that the app id issue could be because I was modifying one of my existing apps, rather than starting from scratch. IHope this helps someone else who experiences the same problem.
I have uploaded apps successfully in the past, but I keep getting the error message "app id already in use" at the moment. I have changed the details repeatedly, uploading a new fba file, but the same message comes along. It seems that I've found a way to break the system, or I have a knack for repeatedly choosing names that are already in use somewhere. Anyone else have this problem? Could it have something to do with updating the tags for the new file at the wrong time? I have even started a completely new app, meaning I have unused apps now sitting there. I emailed support, but so far noone has replied. Any guidance will be much appreciated, because I have spent hours renaming and adjusting code, only to have the upload fail repeatedly. Surely, if the app id really is in use, we could be warned way before going through all this?
