You may need to change the file permissions to make it executable. Try this:

#chmod +x /path/to/btupfile/btup
#chmod +x /path/to/btdownfile/btdown

Are you running these commands as a regular user or as root?

Also, when you get it to pair with each user using 'sh btup', can you ping a website? What is the output from this?

#ping www.google.com

If you get a response you are on your way.

Post back and we'll see what is going on.

Also, take a look at what I use for my N800.

http://linuxgadgets.blogspot.com/