Yes, I think its a bug from gnome, gnome hides xxx.desktop if it link to a non-exist binary.
step of installing deb packages ->
1、dpkg decompresses /usr/share/applications/virtualbox.desktop to system (System found out it links to /usr/bin/Virtualbox but it not exists, so hide it)
2、dpkg decompresses /usr/bin/VirtualBox (till now, the like file appears, but it is late..)
Thus, icon is not shown after installion, but by restarting gnome-panel, it will come out.
Yes, I think its a bug from gnome, gnome hides xxx.desktop if it link to a non-exist binary.
step of installing deb packages ->
1、dpkg decompresses /usr/share/ applications/ virtualbox. desktop to system (System found out it links to /usr/bin/Virtualbox but it not exists, so hide it)
2、dpkg decompresses /usr/bin/VirtualBox (till now, the like file appears, but it is late..)
Thus, icon is not shown after installion, but by restarting gnome-panel, it will come out.