I'm sorry to hear that you've had difficulties with Toast 11. From the many reviews I've read, and the many posts on this forum, you aren't the only one, and to be honest, with all the negative talk about Toast 11 I was VERY hesitant to purchase it recently, however, after trying several of the few other Mac based Blu-ray authoring programs available, and seeing their limitations, I decided to go ahead and purchase Toast 11 directly from Roxio (even though it was more expensive that way), because I knew they offered a 30 day refund policy.
Since then, I've thrown everything I could at Toast 11, not really expecting it to be able to do it all, and yet it's performed exceedingly well, burning and copying, and converting everything I've tried, which includes Blu-rays, DVDs, CDs, and converting files of all types.
I'm running a Mac Mini (late 2011 model) with OXS 10.8.2. I'm using a Digistor DIG-79092 burner (using the optional AC power supply). I use Verbatim DVDs and Blu-rays and Sony CDs. So far I've tried CD-R, DVD-R, DVD+RW, BD-R and BD-RE DL, all with 100% success, no failed burns.
One thing, I feel it's important to have all other applications shut down when I do a burn, feeling it's better to give the full resources of the computer to the burn task. It might be overkill, but it's something I learned when I started burning DVDs 10 years ago, and I've had pretty good success since then, so even with today's more powerful computers I still follow that protocol.
My recommendation would be to first tell us a bit more about your situation and let us see if we can help. What model Mac are you using, and what OSX is currently installed? What version of Toast 11 do you have? What were the original source files you were trying to burn to Blu-ray? What brand of media were you using, and what brand of burner?
Second, and you've probably already done this, but be sure and contact Roxio technical support, providing them will all the information I just mentioned. It's possible they might be able to help you find a solution.
When I first got Toast 11, about a month ago, I was amazed how much they said it could do, and to be honest, rather skeptical, but after reading the manual from cover to cover, and following their suggestions (along with the many suggestions I've found on various forums), I've gained a fair amount of respect for the straight forward thinking that went into developing this program.
Of course it's not perfect. I've found a few minor oddities, but overall I've had a very positive experience, and I'm hopeful that with a bit of research and help from some of the more knowledgeable forum members, that you will be able to get back up and successfully burning Blu-rays soon.
EDIT: Oh, this is something you might try...... when I got this program I also bought a Verbatim BD-RE DL (blu-ray re-writable dual layer) disc and a re-writable DVD, and I always test my burns first to make sure everything is ok, and once I've got things dialed for a successful burn on the re-writable disc I'll then go ahead and burn the regular permanent blu-ray or DVD disc.
For DVDs, before I even burn, once the project is complete I'll go to the FILE menu at the top left of the screen and select "Save file as disc image". This is the file exactly as it will appear on your DVD, and once it's saved I simply "mount" it, then view it with the Mac DVD player, and if everything looks good I'll proceed to the test burn using a re-writable DVD, and if that looks good I'll go ahead and burn the real DVD.
Anyway, the re-writable Blu-ray discs are $10-15, but it seems like a good investment to me. Just a thought.