Driver cob question

Hiya
Im messing around with some mini cobs (not for a grow light actually for some lighting designs), however i am really crap with this sort of thing.
I have a 15w cob rated 240-260mA 45 - 53V
Driver 8-24w 280-300mA 54-108v
1 cob starts smoking quickly, i tried 2, they smoked too.
I dont understand why the driver is cooking the cobs...?
Help!
Cheers

To use them at the full potential you'll need heat sinks.
I have not worked on cobs myself, but I know they get very hot very quickly when run at 100%.