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Okay, I think I've found the answer, everyone:
I had my Xperia X10 lock on me due to too many pattern attempts, and I was pulling out my hair for the better part of a day entering every possible combination of passwords, id's, removing the SIM card, SD Card, battery, connecting to USB, Updating the Phone, you name it....
Basically, none of the many, many tips given by people on the Forums worked. That is, until I tried to change the settings in the phone, during the half-second window of time after ending an incoming call (Despite the pattern lock, the phone will still accept calls.)
I had to call the phone well over a dozen times to finally change the setting, because in that half-second, you only have time for one, maybe two screen taps (if at all). However, the good thing is that the phone stays on the Settings screen it was last on, so step by step, I would call the phone, hang up, select the next screen, then repeat the whole process until I was finally on the screen to deactivate the pattern lock feature. Here's the appropriate screens to sift through, if you aren't familiar with the Phone Settings:
Settings/ Security/ Require Pattern...
After selecting 'Require Pattern' comes the hard part, and you are asked to enter in the Pattern again. Remember, you have only half-a-second to enter it, so make sure your hand aren't sweaty (as mine were, out of frustration) or else your fingers will drag on the touch screen and make entering the pattern quickly very difficult.
After REPEATED tries, eventually I was fast enough, and the phone opened up and everything was just like it was.
After this, I AM NEVER USING PATTERN LOCK AGAIN!!!!
13 of 17 people found this answer helpful.
**copy paste from google mobile help forum**