electrical fault?

hi all, i have an megane coupe y reg (2000) problem is me keyfob sometimes doe'snt open the car, so i put it in the door to open manualy(had the car since new & never had to this before) car wont start too, also it takes anything upto a couple of hours for immobliser light to come back on(been told it resets it's self ?), also happenend yesterday when i pressed the k/fob again to unlock, indicaters normally flash once, but they stayed on permenantley for afew minutes, then all happens again, even AA are baffled, please please please any ideas & cost?? is this the UCH unit or whatever its called???