Hidden sliders lock you out for iPad and iPhone in iOS 5 jailbreak state. This is caused after you restore all your backup settings in from Cydia after jailbreak. For example, Springtomize 5 has the option to hide your Slider. But to unlock, you have to use activator. In order for activator to be installed, you either install sbsettings or activator from Cydia. But neither of them restore from backup; which means if you previously set your slider to hide the slider in Springtomize, and then you decide to restore springtomize, the previous settings will be restored which will lock you out.
To fix this problem, send yourself a message either text message, iMessage or wait for a notification appear and just slide the notification icon to unlock. Use the notification icon as a slider to unlock. From there, you can go to your settings and unhide the slider or use activator to unlock your iPad in a different method. Springtomize is one of the app that can lock you out, there also other apps that can lock you out if you are tweaking around your jailbreak iPad.
My suggestion is, install SBSettings first after you jailbreak your iPad. SBSettings will automatically install Activator. Use Activator to unlock your Home Screen. In-depth how to use Activator is floating around in Google. It is a powerful apps, you can use Activator to shake your device to unlock and so on. It’s a good thing to have as a backup unlock in-case you lock yourself from the Home Screen.
Unless if you prefer to not have a way to unlock your Home Screen, and to unlock it is to iMessage your iPad or send a Notification message via a 3rd party communication software such as SMS to your iPad via Skype or Talkatone or Vonage or if you actually use a real SMS software from Cydia such as SwirlySMS. But then that would be a hassle just to unlock.
Another reason to hide your Slider is to prevent theft from accessing your information. Only you know how to unlock. Either shake, swipe from right or left, swipe from bottom right or left, double tap clock, swipe up or down, or you use your home button to either double press, short hold and power button, single press, Triple press. You can also use the sleep button to double press or short hold to unlock. There’s more to settings you can in Activator, you just have to play with it as a secondary unlock when you hide your slider.