yellowing Oncidium leaves?!

[Ducky87]

Thanks guys. I put it in this bigger pot because teh pot it came in didn't fit it's roots anymore. so i put it in a half inch bigger pot. I'll wash out the old one and put it back in there. as for the potting medium. I think it holds too much water. I'm going to pick up some fir bark from the local pet store so it's in just pur bark and hopefully get it repotted today before I head to work.