Disappearing Icons on Galaxy S2

On my Samsung Galaxy S2, sometimes all of the icons will disappear from the home screens except for the 4 built in icons (phone, messaging, web, applications). This sometimes happens at startup, and sometimes happens after the phone has been running for a while. It can only be fixed by rebooting the phone, although that is not a guaranteed fix. More recently I've encountered an additional problem: Sometimes when the icons disappear, the Applications button stops bringing up my applications menu. Any suggestions on how to fix this?