eps quality

hi everybody,

I have been using matplotlib for some months without any problem and I am very happy with it until recently when I upgraded my OS from fedora 6 to fedora 10. everything seems ok except for that when I save a figure in eps format, the quality of the resulting figure is poor and the size in also smaller than what it is supposed to be.
Is there anybody to help me with this respect?
I appreciate in advance,

sean