I have upgraded my Xperia X10 software to 3.0.1 G.0.75 . Upgrade went fine , but unable to read any application from the SD card, which had the backup/Restore application. So I can't restore my contacts and this is affecting my Business as I am unable to access my contacts. Please help how to recover from this

SOURCE: Unlock code for sony satio memory card

I have the same problem! Tried everything from '0000', '00000', '12345'. Still locked. Help!

SOURCE: cannot use phone function on x10

i have exactly the same problem it is happening to me as it occurred 4 days ago just happened when trying to call it just say call ended and cannot receive and send calls or texts either.
signal strength is full i have hard reseted it and done almost everything my x10 is on orange and i cannot thing of a solution for the problem i go it online and cannot get return it to anyone when i revived it, it was fine its just happend i hope there is a solution because i love the phone.

SOURCE: how can we install new software & game from pc to xperia

Download and install 'Astro File Manager' from the market for free.
Connect phone to pc and save the app or game you want to install to your SD card.
Disconnect phone from pc.
Go into Astro on the phone - you can now browse your SD card or phone.
Browse to the game or app and click on it.
Select 'Open App Manager' and you then have an option to install.

Once the app is installed, you can use the same procedure to un-install it.

NOTE - if you're downloading Android apps from the internet rather than the market, a lot of them are not actually compatible with the X10, but there are some really good ones out there.

SOURCE: I bought a new Xperia X10 and i want to copy

Yes indeed you can copy your sim contacts to your X10

Just insert the sim into your x10.
Turn on the handset
Open main menu by tapping bottom of screen. Or touch bottom of screen and drag finger upwards.
Find "phonebook" and tap that.
Now your phone book is open Press the Bottom LEFT button on your handset not the screen the actual button.
A menu will pop-up so tap the "More" option
Then tap "Import Contacts" from this menu
Then tap "Sim Card" from the new pop-up.
The rest should work for you.

I hope this helps and I hope you enjoy your new phone. :)

SOURCE: Sony Xperia X10 Unlock Attempt Left

No way of finding out how many times the wrong code has been entered but...

You can still unlock the phone by using
"totalgsm"
software and your data cable that you got with your handset.

You will need to pay for some credits for the software to unlock your phone and your computer needs to be connected to the internet whilst it does it.
It's worth looking around for different prices too. I looked for a c902 and found prices ranging from £25 to £7 after you work out the exchange rate from Dollars to Sterling.
$40 is the starting price see how low you can find it. :)