Sunbeams node fail

I wanted to add some god rays to my work, but for it didn’t work well. For an unknown reason it used some alpha channel.
Here is the original (I don’t own any of that design):
http://srv1.jpg.co.il/6/5523881009d36.png

and this is the resault with the sunbeams:
http://srv1.jpg.co.il/7/552389ea739ac.png

do you have any idea why it is acting like this?

Your multiplying each pixel by a fraction factor. That operation takes all channels into account, also the Alpha.

Cheers!