Many customers are running into an inst installation prerequisite
  error when they try to load inventor_dev 1.1.2 onto their IRIX 5.2
  system. This error is due to a name change in c and dev subsystems
  between IRIX 5.1 and 5.2. The new name is c_dev. The fix is to load
  the *new* inventor_dev 1.1.2 (part # 812-0136-005) made for IRIX 5.2
  that came with the Open Inventor 2.0 Development Package. This
  version is smart enough to do the right thing. Unfortunately, both
  the *old* and *new* inventor_dev 1.1.2 are barely distinguishable
  only by their part number and content. The new inventor_dev 1.1.2 has
  a Copyright of 1992-94 and does not contain inventor_eoe 1.1.2.