I have a 1 year old Dwarf Meyer Lemon tree that has thus far lived a very happy life in my room, but is now experiencing some leaf loss and discoloration. See the below links for photos of the leaves. They have developed areas that are lighter in a blotchy pattern and are yellowing slightly as well. On the underside of the leaf, the surface has become rough and broken in the lighter areas, almost resembling a bruise. Apparently plants can also experience edema, so this may be what is occurring. I also have a Dwarf Tangelo and Dwarf Orange in identical conditions that are the picture of health. Does anyone have any idea what the cause of might be?

http://imageshack.us/photo/my-images/34/dscn1394l.jpg/

http://imageshack.us/photo/my-images/32/dscn1396z.jpg/

http://imageshack.us/photo/my-images/96/dscn1399mf.jpg/

http://imageshack.us/photo/my-images/846/dscn1398y.jpg/

Some details about the plant:

-It has flowered and set fruit three times already, new crop of lemons has just started.

-It was recently pruned a touch to help keep the tree compact.

-Planted in 24" plastic pot with standard garden store potting soil (this probably should be upgraded to a better mix)

-Sits in large south-facing bay window with tons of sunlight year-round (Berkeley, CA).

-Fertilized monthly with foliage pro.

-Has to stay inside, no outdoor space.

-Treated with neem oil twice to kill scale

Thanks so much for your help!