Not recognised any sim always in flight mode

[happyseacat]

Hallo Dear Friends,
After 5 months cool job my phone 2.3.3 GT-I9100 SGS2 running India distribution unlocked. Not rooted start showing constantly an icon of a plain as it was in flight mode and if you go to settings it shows that the flight mode is off. Also it is not recognising any SIM. Currently I am in UK.
Any help or advice?

[Couchwarrior]

Had the same problem with a new phone i bought from 3 it was branded and locked, i unlocked it and then it wouldn't work with any sim. Flashed it with 2.3.6 and everything worked, now on ICS