Posted: 17/10/2013 at 08:09
They need a sheltered spot - I wonder if the leaves are suffering wind burn. If the soil is damp and the leaves browning and look dry then it sounds like wind damage.
They need well draining soil. There are a large variety of Acers and all prefer but do not need acidic soil as KEF has said. If the pot is waterlogged then you tend to also get branch dieback, though wind damage can also induce that.
I would check drainage and make sure your Acer is in a sheltered spot. It should put out new leaves in early spring.