I added xpad to the panel. It works fine. I just have not been able to an icon to the panel item. It is auto started so
I was able to make the menu entry use the notes plugin icon. What's here is the last of many attempts.
I love my Unix desktop and xfce is a fine option for those of us who liked (or were okay with) kde3. Howsome ever my system has more than 450 components. I told you that so I could tell you how I 'fixed' the missing icon problem. since I do not want kdelib I need a PDF viewer. I tried Evince wich broke gnumeric (don't ask how - it did). So I backed it and its dependencies out of my system. This caused a lot of issues so I had to force some running components to terminate and I rebooted.
YEP - you probably guessed, the icon I had assigned to xpad appeared on the panel. How great is that???
Glad, it auto-solved itself.
But a general rule is to NOT use the extension in the icon name (svg, png etc.). As far as I remember, you can use the extension if you put the entire icon path but otherwise you should use just the icon name.
I tried almost any combination you might think of. My most 'inventive' one was to add a panel entry for an xfce-plugin and then edit xpad into that entry. I think what happened (most likely) is that one of the packages I added did something to the menu structure. Then when I backed out evince and its dependencies the menu glitch was corrected. At some point tonight I will check file modification times and see if I can get any clues. I made no panel changes. The only thing I did was uninstall and reboot.
What I was mostly, was amused. With all the combinations of packages, hardware, operating systems and people its pretty amazing it all works.