you mean you updated to gingerbread again after samsung fixed it? i think krospyke thread here regarding gingerbread update has a procedure after you flash your phone for the camera fix

 

try rebooting the phone. if that doesnt work, clear the cache.

you can clear the cache by going to recovery mode. you can do that by holding vol up + home key, and while holding, press power button. your phone should be off when doing this.

 

no. this is not a reset. you do this after updating. i assumed you have just updated because camera didnt work. it cleans all the "left overs" from previous os, i think.

...oh wait.. you said it was unbricked by samsung techs and then camera didnt work? maybe its better to send it back to them for backjob repair/maintenance.

 

My front camera not working.While giving self shot the camera shows message 'Warning Camera Failed',but my back camera is working. May I know what I will do now to Start my front camera.Plz Help.

 

did you just flash/update your phone? if so, flash it again.

quoted from the update site..
"TO: EVERYONE HERE

Just reflash the firmware if you have any problems, it will cover any problems you have with your phone..........For Gingerbread frimwares, they have to always be flashed twice as ODIN cannot cover the modem and some other rfs files during the first flash."

 

and from what i have been reading on blogs regarding XXKPH, you must flash first with XXKPE before flashing XXKPH