ive sent off a few phones that have had custom roms and never had a problem?
just out of interest guys how do you get rid of the triangle at boot ?
is it removed when you flash back to stock ?
OT
root the phone, download Triangle Away by chainfire.
you can find it free here http://forum.xda-developers.com/showthread.php?t=1494114 or for a beer on the play market.
I did it on mine, no problem at all.
follow the instruction carefully, that .apk could brick your SGS2
A word of warning - don't flash a 4.0.4 ROM at the moment, as if you wipe in CWM recovery (or even sometimes stock apparently), it can properly brick the device.
Using Odin, put the phone in download mode and flash the latest 4.0.3 XEU unbranded ROM. Then you should be able to use Kies as normal, which will update you to a 4.0.4 if you want. Just be careful...
so you cannot use clockwork with 4.0.4 at all? even if you update via kies?
if so it looks like 4.0.3 will do but what are the differences between the two?