wandering icons

[seasider]

About every third or fourth time I switch on my phone all the icons have disappeared.
Switching off and back on works, although sometimes I have to do that a couple of times.
Any help would be appreciated. Thanks.

[Marshmallow]

Leave your phone for a minute after turning it on, to allow the media scanner to complete before unlocking or entering the sim lock pin.

[seasider]

Thank you for responding, but I don't have a sim lock pin.

[Professor Yaffle]

About every third or fourth time I switch on my phone all the icons have disappeared.
Switching off and back on works, although sometimes I have to do that a couple of times.
Any help would be appreciated. Thanks.

Are you using a custom ROM or just the stock firmware? If the former, it may be the launcher. If the latter, try another launcher such as Launcher Pro from the Market.

My phone (Galaxy S) is rooted and I occasionally get the icons shuffling around after an app update - I just go into Titanium Backup and restore the data (only) for Twlauncher (Samsung's default Touchwiz launcher) and when I exit Titanium Backup, Touchwiz refreshes itself and all's back to normal with no reboot required. I backup system data and apps nightly via a scheduled series of backups including a reboot after the last one to freshen things up (always a good idea).

Also, worth ensuring you are on the latest firmware (check via Kies or the phone's OTA software update).