Trouble with folder icons and names

My husband's Mac is doing something strange. Sometimes, when he opens a folder, then goes back to the main folder, the icon names are far from the folder icons, and overlap the icons below them. They should be directly under the folder icon, but this doesn't always happen.
He has tried changing his icon settings, and sometimes it helps, but then he will open a folder, go back, and the folder icon names are again far below the icons and over the tops of the folders below them. Does anybody have any idea as to why this happens and how to fix it permanently?

What version of the OS? (Leopard 10.5.x, Snow Leopard 10.6.x, Lion 10.7 ...?)

Maybe the finder.plist file is corrupt. Move it to the Desktop and Restart. Find it here:
/Users/YourUserName/Library/Preferences/com.apple.finder.plist

A new plist file will be created.

He is running OS X 10.6.

We have tried several times to arrange the files, and it helps for a while, but sometimes when he comes back into the folder, they are messed up again.

This is happening on the desktop, right?

What happens if you put all that stuff where it's actually supposed to go (for example, (User)/Documents) rather than on the desktop, ie clean the desktop?