Q: sim card not valid after update to ios 5

Thank you!!!

sounds like a good solution! I should have the serial number back at home (shouldnt they have it too since I had that first replacement???) do you think is posible to contact and fix this problem by email? (i dont have any phone to be contacted unless I buy a new phone... )

thanks again

This problem has happened to me twice. The first after upgrading to iOS5, the second when I did a full reset of my iPhone. Both times I would get the message 'Please insert a valid sim card'.

The problem was finally fixed yesterday. I was on the phone with Apple for about 30 minutes and it was discovered that when my previous iPhone 4 was replaced (for a dropped screen) the Apple employee who did the exchange must have entered my serial or IMEI number incorrectly. This would mean that everytime I did a reset of the phone the problem would occur.

The only way for this problem to be solved is for Apple on their systems to correct the information. Apple did this on their servers and a few hours later my iPhone was working again. A replacement phone will only solve the problem temporarily - as soon as you do a reset or update your software the same thing will occur so Apple must update your data on their servers.