Hi,
This is not a problem with the Sim. This is a fault with sony ericsson phones.. I have a w810i and this happenens at least once a day... the phone will sitting on my desk then all of a sudden say inactive sim then crash... I have spoken to vodafone and they just ready from text books try and fob me off with its the sim card.. I have had my phone for 2 yrs from new on a contract and can't do a thing about it!! They say send it back.. sent it back.. comes back the same.. problem is intermitant!! i am going crazy trying to find a fix to this!! good luck. :-)
karen
April 2009