Search2Play broke my Samsung Infuse's back button. How can I fix it? I have a Samsung Infuse 4G, rooted and unlocked.  I installed Search2Play and it broke my back button.  I uninstalled and unrooted, then rerooted, but the back button is still not working. Could someone please help me fix this?
You'll probably want to wipe everything and reflash your ROM.  This XDA post has everything you need:


  What this is:
  
  A package to return your device to a completely stock state. It differs from h8rift's packages in that it includes a PIT file to repartition your phone. This is especially useful for those who accidentally flashed the wrong PIT (cough... bella) or screwed up their partitions some other way.
  
  Is this dangerous?:
  
  No. The PIT file I created has been tested and confirmed working by myself.
  
  Instructions:
  
  
  Make sure the drivers for the Infuse 4G are installed (installing Kies is the best way to accomplish this)
  Download and unzip GTG's_Ultimate_Unbrick.zip
  Run Odin3 v1.7.exe as administrator
  Place your phone into download mode (pull battery, replace battery, press and hold both volume buttons while plugging in the USB cable)
  Make sure your phone shows up in Odin as COM##
  Click the PIT button and choose infuse.pit (and make sure Re-Partition is checked)
  Click the PDA button and choose PDA_UCKD5.tar.md5
  Click the PHONE button and choose PHONE_UCKD5.tar.md5
  Press Start
  In the rare case that it finishes and your phone proceeds to boot loop, pull the battery, replace it, press and hold both volume keys and then press and hold the power key, keep holding all three buttons until 3e recovery comes up, select "delete all user data", and finally select "reboot system now".
  
  
  ----Download----
  GTG's_Ultimate_Unbrick.zip (183MB)


Note that Odin is very powerful and, despite the fact that the post says it's not dangerous, Odin can brick your phone.  Proceed at your own risk.  That said, I've used Odin dozens of times myself and it's saved my phone several times.