Hello,
Thank you for contacting National Instruments.
To answer your question, your NI AT-GPIB/TNT card should work fine with LabVIEW 6.0.2. The functionality of the card really depends on the version of NI-488.2 that you are using.
My guess is that you have a corrupt or more recent install of NI-488.2 on your system. The latest version of NI-488.2 that is supported by your card is version 1.7. Try removing NI-488.2 from your system using Add/Remove programs. Then download NI-488.2 version 1.7 using the following link:
http://ni.com/support/gpib/versions.htm
After you reinstall version 1.7, I believe it will work fine.
I hope this helps!
Matthew C
Applications Engineer
National Instruments