Sculpty Beads

[lower-class.livejournal.com]

I made my first set of sculpty beads tonight. I got the rolling part and the cutting part and the making holes part. Now I bought a toaster over purposely to cook them in. I followed all the directions...and cooked them for 15 minutes like it said to.
All my beads burnt. Maybe I should have kept a better eye on them, but I went and ate dinner while they cooked on the porch. I went out and saw that they were burning, so I turned the toaster over off and pulled them out. They were not even done cooking all the way. They were still soft in certain points. So I let them sit for oh another hour or so in the toaster oven.
When I went to clean up and put the toaster oven away, they were still burnt but they had hardened.
My question is, did I do anything wrong? Like how can I make it so they don't burn?
And also, if I cook them at oh say 250 degrees (instead of 275) will they still harden?
And what if I stop them at 10 minutes or something. Will letting them sit in the toaster over harden them?

Any suggestions or help would be much appreciated.

This was my first time ever making them beads. I was sad at the way they turned out. *sad panda*