Android let you configure if you want to look up your cellphone screen using a pattern.

Normally this works wonderfully and maintains away some people out of your data, however when you try to many times the system fall back to your google account authentication.

In normal conditions this worked for me. However looks like in the android-1.5-cupcake there is an error in this process and the system can't authenticate against the hash stored password inside the phone.

This bug is very ugly because if you didn't find a workaround you must to reset your phone a lose all your data.

Googling a little I found that workaround. Saddly only works with developer phones (I have one) or phones that have root access.

The thing works like this:

1. Download the Android SDK
2. Using the adb tool access your device [*]
   

      $ sudo adb -d root
      $ sudo adb -d shell
   

3. Change the internal configuration at: data/data/com.android.providers.settings/databases/settings.db
   

      # sqlite3 data/data/com.android.providers.settings/databases/settings.db
      # sqlite> select * from system where name like '%lock%';
      # 21300|lockscreen.lockoutattemptdeadline|112230410
      # 21577|lockscreen.lockedoutpermanently|0
      # 21789|lock_pattern_visible_pattern|1
      # 21790|lockscreen.patterneverchosen|1
      # 21791|lock_pattern_autolock|1
      # sqlite> update system set value=1 where name in ('lockscreen.lockedoutpermanently','lock_pattern_visible_pattern','lockscreen.patterneverchosen','lock_pattern_autolock');
   

4. Restart your phone normally

[*] I use Ubuntu and by some reason I have to run adb as sudo to make it work.