Strange, I haven't seen that happen on my D3 with Steel just yet. I've seen this happen on my Fascinate and Eris before. It tends to be an icon cache bug. Typically a reboot fixes it. If not, you can use CacheCleaner(or whatever other cacheapp you prefer) to flush out all your cache then reboot into CWM and format your cache then reboot. then the icons should reload just fine.