Hi,
The icon.x files are nothing to worry about. They are used to determine the icon that should be displayed in browser listings for all the file name extensions that Yummy encounters as you use it. It seems you must have a lot of files with numerical suffixes. In any case, all those files are zero bytes so they are harmless. If you wish you can delete the whole lot and Yummy will re-create as necessary.
The rename issue is an odd one - I'm not sure what's happened there. I will check into it.