INDI SBIG driver uses SBIG Universal Library and it is mostly working well under Linux but there are a few bugs. One is the inability to control the fan as reported by some users. I was following before with Jan Soldan, but now I'm not sure who is responsible for the SBIG Linux Library?
I've bumped into this problem with our ST-10XME. With a recent load of the linux support, after turning off the fan, you cannot turn it back on. I've traced into the code, and the problem exists somewhere after the call into the sbig universal library. Doesn't matter what state you set for the fan flag, it returns with 'fan turned off'. A full restart doesn't fix it, unless we physically unplug the camera from the usb port, not an acceptable solution for remote operation. I've tested on both 64 and 32 bit x86 architectures.