I have a similar problem with a seemingly png file. I recovered some jpegs from a recovered flash disk but I can not open them. irfanview gives the error "cant read file header unknown file format or file not found!"
I tried to open them with notepad++ and a hexeditor. but my lack of knowledge prevents me to do anything useful
I would really appreciate if someone take a look at the file and confirm me that it is hopeless to recover them..