I was facing the same issues after I updated the GingerBread from the Samsung website. I then used this defective OS device for 10 days and then I was tired when calling or unlocking the phone screen it was giving a hard time.

If anyone had the same problem regarding to the touch screen, wifi and calling issues they can use the following link to update to GingerBread stocked version. They have explained how to install it in very detail and according to me anyone can do it by self. Thanks to xda developers. My Samsung Infuse is now working awesome as it was before on froyo.... yuhu.. :-)

http://forum.xda-developers.com/showthread.php?t=1613523