Lost mode in iCloud. How to deactivate ?

Hi all.

Today I've lost my iPhone 4 - I went to 'find my iPhone' on my wifes iPhone and logged in to my account. I traced it, found it - and activated "lost mode". A few hours later I picked up my iPhone and the battery was empty.

I charged the phone and tried to start the phone up. Now: All I can se as the velcome screen is the USB-symbol. I have no possibility to unlock it with the code I provided it with earlier today. Simply nothing happens.

I startet up my computer and logged in to iCloud. Here I clicked on the "find my iPhone" app and tried to remove the "lost mode" state. But as the iPhone isn't online I cant seem to unlock it from here..

H E L P !!