Hey there.
I have been able to confirm this w/ the latest OSS Version of scalr on both Chrome and Safari (latest of each, on up to date OSX).
Here's what you need to do in order to reproduce. I have attached screenshots below to demonstrate.
0) create a farm or edit an existing farm with at least one farm role set to use Chef for bootstrapping.
1) from the "bootstrap with chef" tab, change the chef environment from it's current setting to any other setting. In the included screenshots, i change an environment from dev to dev14.
2) the run list for the node (role `graphite`) has been changed to BLANK.
3) Saving the farm will result in future nodes coming up w/ an empty run list with the correct environment. Cloning this farm will result in a new farm, with the existing roles. The chef environment will be correct, and the run list will be BLANK