Some days ago this problem started happening when I receive a call with my HTC Desire HD. I press the button to take the call and this alert pops up, immediately after I'm asked to enter the pin again. Today i found out that even when this occurs I can still talk to the person, but I wonder why is this happening. It didn't happen before. I don't know what is it that I did that changed something, i just updated the OS to 2.3.5 some time ago and some apps as well. help?