NI-VXI 2.1.0 officially supports Red Hat Enterprise Linux 4.0, Suse Linux 9.2 and 9.3, and Mandrake 10.0 and 10.1.
It has been observed to work with vanilla kernel versions up to 2.6.17 (I think - it may only be 2.6.16).
With kernel version 2.6.18, they did indeed introduce a mutex type that interfered with the one already declared in the NI-VXI source code, which breaks the build.
I'm glad you were able to find a solution to your problem.
