Did you hand dye this yourself? I would make a quick contact with the people at Dharma Trading. They specialize in this sort of thing.
http://www.dharmatrading.com/index.html
Many dyes are picky and depending on how the fabric was processed before it was dyed will be a factor. I would definitely not do anything with heat until then. This is the precise reason I prewash everything separately and check the water. If I suspect I have a bleeder I will do it again and recheck the water. It may take a little more effort but it saves on the frustration of seeing a lot of word ruined later.