LXPanel random missing icons

[edward]

I'm having a similar problem with my LXDE install in a VirtualBox and it's been reported to the distribution as a bug. If the panel appearance setting is on either System Theme, or Image (using the default background.png), some of the application icons are not appearing in the window tabs.

If the setting is on Solid Color (with opacity), whether using a color, or a 100% transparent panel, the window tab icons appear as expected.