Sounds like it needs ventilation if an eclosed cupboard ie top, sides and bottom.
Mines in a cuboard with no top or bottom only stabliizing bars back and front to hold it together so heat disburses out top of cupboard accelerated by draught drawn in from bottom so no door bowing.
So you've got to vent the cupboard.
BB
January 2011
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cabinets and cupboards.