Hi Paul,
In order to convert VIs to a previous version, you open the VIs in 8.0 and choose File - Save for Previous Version and then choose 7.1. I tried to convert the VIs, but there are commands used in the VIs that are do not exist in 7.1. I understand that you do not have 8.0, but I would suggest using this version. Is this an option for you?
Amanda Howard
Americas Services and Support Recruiting Manager
National Instruments