Hi!
I got an Samsung I9001 which had some Problem with 900mhz networks.
In most cases the phone has got a good signal but can't make any calls. And sometimes it has got no network but if I search for the networks thw phone finds all newtorks.
If I use a simcard from any provider which works in 1800MHz everything works finde and I can make calls.
I found some thread with I9000 network problems and they told too solve it with an update, coz bootcore and modemfirmware are not compatible.
So i updated the phone with Samsung KEYS (Does it update bootcore and modem part too?) and also made a hard reset. But w/o any result
Regards
Shaxx