/dev/comedi0: No such device

Hi all

I am having trouble opening up my comedi device, an NI 6221. On executing
the line:

device = comedi_open("/dev/comedi0")

/dev/comedi0: Permission denied

the file /dev/comedi0 has permissions rw-rw---- (660) root root. When I
change the permissions to rw-rw-rw- (666) I get the error message:

/dev/comedi0: No such device

When I do 'lsmod', it shows that ni_pcimio is loaded.
We've compiled 0.7.73 on a kernel 2.6.15 on an ubuntu system.

How do I get my program to see the module?  I am assuming that for some
reason the module can not be seen.

Thank you for the help guys and gals.

George