Whoops, my apologies. For some reason I thought you meant ripping -_- ugh, been at home with the non-techies for too long (they use "burn" and "rip" interchangeably).
What kind of disc are you trying to burn, data or movie? It might be worth a shot to give the built-in disc utility a try if you're trying to burn data or a disc image to a blu ray. Just because OSX doesn't natively recognize blu ray movies doesn't necessarily mean it won't recognize the format at all.
Unfortunately, Toast has the most face through a google search. If you're trying to burn blu ray movies, then RevolverHD might interest you (
http://www.shedworx.com/revolverhdmac) it's got a free trial for you to take for a spin to see if it works. It might handle data, too, but at first glance it seems to be specifically for videos.