I've had a similar experience a couple of times. The first time I just had to unlock the car and try again.
The last time was when I last had the car dyno'd
I couldn't get the boot open no matter what. The roof was down, and the car was locked. I had to put the roof up and unlock the car before it would let me open it.
Some weird fault, but it hasn't happened since.
BTW achieved 300hp at the wheels with a stock 35is.