I've a strange problem with my icons. Icons I set manually for different folders in various drives and at the desktop disappears.I got the same problem when I was using ubuntu 9.10. Now I am using Ubuntu 10.04.

The icons appear automatically when I download some packages from synaptic. When I shutdown my PC & open it, I got the same problem.

But the icon of INSTALLTIO drive never disappears.

You can see in the screen shot, icons for fire-fox & New Volume have disappeared whereas the icon of INSTALLTIO has not disappeared. I've set the icons manually for them. The default icon of chrome is not affected by this problem.

Why is it so? I've much distressed by this problem?

I miss the screen shot...
maybe not important, but

and sorry, I don't know the answer (I wanted to give some suggestions, but they were for KDE - not for Gnome (default DE in Ubuntu))

so...

Please have a look at the screen shot of my desktop.

your own icons: are they always available (I mean, are they saved for example in your home-dir?)
=> if they are on another partition / usb-stick / ... which has to be mounted on/after the start-up, it is possible that they aren't found soon enough to be used!
(maybe, the DesktopEnvironment automatically makes local copies, but I'm not sure about that)