What software are you using to skin with?

Richard are you using the latest Iconpackager... 4.09[b].003 (x86)?  Yeah, cos I've had that happening to some app icons on occasion.  What I do as a workaround is open IP and reload the current package... but yeah, it might be a bug they need to look at..

Search Hidden folders/files for IconCache.db . Delete. Empty Recyle bin. Reboot.

When I open lets say Vue 6 infinite folder it seems like .exe use to have the vue icon but now all .exe's, .dll's and so on are just plain white folder icon, and when you right click on .exe shouldn't you have option to change icon, I don't. The other day it seemed fine then all the sudden all icons that were pinned to start menu just showed plain white folder instead of application icon.. I don't know what happened but all files still work it just looks bad... Also found IconCache.db and deleted it and also in recycle bin and restarted, but nothing changed..