This has been a known issue for some time now. Personally, I had it in 2.0.1 stock, rooted and running the DroidMod ROM. I uninstalled some applications I didn't use, and it seemed to go away for a while, and then came back, but it seemd to be fixed by hitting the home buttong a few times repeatedly which was nicer than having to reboot or close the home process. You can go the the application manager and filter by running and slect home and then choose the force close option and wait a few seconds and that'll fix it faster than rebooting. Also, after installing helix launcher I never had the problem again. I don't know if it is still happening and Helix isnt impacted, but only the stock home screens are affected, or if Helix recovers from it automatically, if helix fixes it or what, but it's an observation. I've also not noticed it since updating to the 2.1 rooted ROM.