Hi, I'm having the same issue. I flashed the phone to stock firmware. My about phone displays:
Firmware version: 2.1-update1
Baseband version: i570EXXJD1
Kernel version: 2.6.29 root@SE-S601 #2
Build number: ECLAIR.XXJH6
How do I revert back to the stock kernel version? It still displays root@SE-S601#2. I'm not rooted anymore though, checked with rootchecker app. Will the kernel version give me problems if I give the phone in for repair?