i have the same problem! my brother entered the unlock pattern too many times and the google account doesn't work!! ahhh

 

look here:

http://androidforums.com/sony-erics...tern-attempts-sony-xperia-x10-locked-out.html

 

asking for gmail username and password bt it doesnt work !! really frustrated with this phone atm ..anybody any ideas at all because everythng ive seen on other sites doesnt work

 

if all else fails connect it back to the pc and do a full repair via the update tool...but you will loose all information on the phone and restore it back to new

 

According to sony ericsson x10 user guide, It says:

"If you should fail five times when you draw the unlock pattern on the screen, wait 30 seconds and then try again."

Hope this helps