Prompting "Are you sure you want to shutdown your computer now?" and konks if idle...

I own a MBP 13" which is 7 months old. I have been having a serious problem for the past four days.

1. Sometimes it konks out during the startup apple logo screen.

2. When logged in it keeps prompting " Are you sure you want to shutdown your system now?" with options "Shutdown, sleep and cancel". Everytime I cancel it reappears when left idle for 5 secs and have to cancel it otherwise it shuts down the system.

I have been talking to the apple support team for the past four days for technical support related to software issues.

I have tried every routine advised including software update and finally reinstalling the OS. It keeps recurring. The support team says it might be a Hardware issue and has asked me to take it to a service center.

I have also run the Apple Harware Test which came out "No problems found!".

I also tried googling the problem online only to find one such thread but sadly without a solution.

http://sonsofsamhorn.net/topic/58629-are-you-sure-you-want-to-shut-down-your-com puter-now-randomly-appearing/

I am leaving to the service center now. Please help!!