USB mode and the PIN window

Hi,

I recently activated the PIN screen on my phone. Now whenever I connect my phone to the PC to transfer some files, the PIN screen will take over while the phone is connected. So when I want to leave the mass storage mode, I'm unable to do so, as the USB window is gone. I enter the PIN and find myself on my phone with the SD card unmounted. The only thing I can do then is to restart the phone, which is quite annoying. I guess this is not working as intended, so what did I do wrong?

 

Maybe you misunderstood my problem. I want it to switch to mass storage mode. That works without a problem. But then there usually is the orange Android with the button to switch back to phone mode on the screen, right?
Well, since I activated the PIN screen, this PIN screen takes over after activating storage mode. So all I can do is enter the PIN and then I am on my home screen while still in storage mode and I have no idea how to get the phone back to phone mode from there without restarting the whole phone.

 

Sorry for the late reply. Didn't see that someone replied because I never get email notifications. >.<
It's a Sharp SH-12C. When the orange Android screen disappears the notification bar disappears too. The Android version is 2.3.3.