I recently encountered and fixed yet another NetExtender problem on OSX 10.6.8 (Snow Leopard) when one of our users unadvisedly installed an older version of NetExtender over version 5.5. Here's the fix:
1. Delete the NetExtender app.
2. Delete the /etc/ppp directory (at Terminal, type: sudo rm -R /etc/ppp)
3. Re-install NetExtender from SonicWall's demo site:
https://sslvpn.demo.sonicwall.com/cgi-bin/welcome
This will get you a working copy of NetExtender 6.0 (the current version at the date of this post). Hope this saves you some time and frustration!
I'm getting timed-out when trying to connect to this sonicwall.com page. Any suggestions?