Hi Paul, > checking for kernel version in version.h...t.c: In function ‘main’: > t.c:4: error: ‘UTS_RELEASE’ undeclared (first use in this function) This is now a known problem with the pctel driver and 2.6.18 kernels onwards. As you have discovered this symbol is now defined in linux/utsrelease.h. However, this is not the only problem, and a new release of the driver is being worked on in order to be compatible with 2.6.18. Please bear with us whilst we complete the new release, which will be uploaded to linmodems.technion.ac.il when ready, and will also be announced on this list. Best regards, Robert (pctel driver maintainer)