Ficus Benjimana - Dropping Leaves

[Brian]

I have a Ficus that I repotted about 1 year ago.  At first, it thrived.  New  
growth, nice healthy leaves, etc.  Over the last month, the leaves have been 
turning brown and dropping.  Is this normal for an indoor Ficus?  I don't 
remember it doing this last year.  I'm by no means a plant expert, but I 
always seemed to be lucky with this one.  It's in a pot that has a resivoir 
bottom, and I keep it filled.  I use Miracle Grow(tm) on my plants.  Am I 
over-watering?  It's in a room with moderate afternoon sunlight.

Any suggestions would be appreciated.

Thanks,
Brian.