I've been out in the sun (can't be anymore than 23 degrees though) and had my blackberry curve with me.
Since I've brough it in the main button has went 'soft' It feels really warm and squishy. I left it in the kitchen to cool down and the button went back to normal, felt hard and was making a slight clicking noise when i used it, however since I've used it its went back to feeling soft.

All the other buttons are normal! Help!!