Hi Sang!
I try using your plugin with RPG Maker 1.8.1 and it works just fine, I found no problem about icon being disappear.
So i guess the latest version break your plugin? nonetheless, if you can update your plugin to work with ver 1.9.0 that would be great.
For now I'll be using RPG Maker 1.8.1.
Cheers!
No, I playing your demo (v130) and add nothing to the demo.