I have GT-P1000 (about 5 yrs back from Samsung shop). Upgraded to Gingerbread about 1 year ago. Two weeks back i rooted with last known config as -
Firmware 2.3.3 Baseband P1000DDJP4 Kernel 188.8.131.52 root@SE-S605 #4 Gingerbread DDJPA
Two days back i installed AppManager[aka Uninstall Manager] from EasyAppStudio) and this app "took over" the home screen and does not exit the app (but kinda of swipes right and displays blank screen). Though i was able to use all other apps through this app. I wanted the main home screen so i uninstalled this app. Again same thing but this time i had no access to regular apps. Though i could use soft and hard buttons shortcuts to pull up apps i knew.
Then i hit hard-boot, it now back to original look and feel but home screen problem remains. And only thing i can do now is to use long press on home to bring Task Manager, or pull down the status bar.(Locked screen still works and i can unlock the "blank" home screen.