Do you run SmartFTP under the same user as when you manually add the items to the Transfer Queue?
Is the process (SmartFTP.exe) running? You can use taskman to verify this.
>how can I find out what SmartFTP is doing/has done in Queued Transfer mode? Is there a log file?
You can enable logging in the menu: Tools -> Settings: General -> Advanced dialog.
If you want to write a small vbs script you can programmatically enumerate the items in the Transfer Queue. You need the SmartFTP Client SDK to do this: