i've been using my international S1Oe for about a year and a half now.
I'm from Singapore and from the moment I got the phone I have been flashing the updated German firmware since they always get the updates first. Everything has been going smoothly till 1 week ago when suddenly my phone would bootloop with the SIM card in it. tried to factory reset and nothing worked.
went my phone to samsung service centre and they told me that my motherboard needed changing and quoted my $480SGD. obviously i said no and took the phone back home.
out of curioisty, i flashed my phone to my local firmware. and weirdly, the phone started working fine with the SIM card in it.
not sure what happened or whether the telco pushed down some changes via the SIM card but the phone now only works on Singapore firmware and not the EU firmware even though the hardware has always been the same.