Spots on top of leaf - help?

[hypersparkle]

Hi there,

I have had this phal for 2 weeks. It's my first orchid (now have 5 more heheh. I'm addicted!!). When I got it had a spot that looked a bit like an injury - just a dent more than a spot really. It's spread now.

It's on a shelf by a windowsill shelf. The shelf comes out from the window sill into my office, so it's not directly in the window, but very close. It's a SW window. I had to repot it due to root rot (so wet it strongly smelled musty and rotten). It's now in one of those nice "ultimate orchid basket"s and sphag (I'm a bit of an under waterer).

Here are pictures:
- Top of leaf

- underside of leaf

Any ideas??