Lab Duck,
The 6221 is one of our M Series DAQ boards that has improved accuracy, higher resolution, lower cost per channel and more I/O channels. The driver needed for this board is NI-DAQmx 7.3 or greater. NI-DAQmx is compatible with LabVIEW 7.0 and higher. The best solution would be to upgrade to LabVIEW 7.1. Aside from the increased driver compatibility, there have been several enhancements to the development environment of LabVIEW over the past two revisions. You can try a free online evaluation of LabVIEW 7.1 at : http://digital.ni.com/demo.nsf/websearch/CE34B1339DE04F2086256E930074129F?OpenDocument&node=1381_US
Although an upgrade to LabVIEW 7.1 is the best option for functionality, the link below will take you to the compatibility VIs for Traditional DAQ. This will allow you to use the Traditional DAQ API to program for a board that only works with NI-DAQmx.
http://digital.ni.com/softlib.nsf/websearch/9D67F671BCC6850586256E630059308B?opendocument&node=132070_US
Cheers,
Brett
