connections starts up fine, but the SCO connections doesn't start at all. When inspecting the loaded modules with lsmod, SCO is not loaded.

why not modprobe sco? was it not built as a module for your kernel?

The question is, is SCO working with version 2.15?

i can't really speak to this. i think an old kernel version is likely to be more trouble than old bluez.

I have compiled the same application on an ordinary PC with version 3.9 and 3.11. ACL and SCO works fine. lsmod shows that SCO is loaded.

I'm using a USB dongle for the moment, but shall use UART instead, because more than one SCO channel is not working on USB. However, it is possible to open two SCO connections on the PC with USB dongle, but not communicating it seems.

there was a dynamic alternate setting patch posted on bluez-devel a few weeks ago that would allow multiple sco through usb. it requires the latest flowcontrol patch to be applied first.

brad