Whats wrong with this leaf?

[greenbean]

I don't have much experience with orchid diseases, so there may be some disease causing this, but it sounds like too much light. Is the orchid right in that SW window? That's way to much light for Phals. You can try moving it at least a couple feet from the window or moving it to an east window or west window that doesn't get sun until really late afternoon. Another factor to consider is temperature. What temperatures are you giving your Phal?