[newbie] Modem Lock

[scheck]

I can dial my ISP as root using DIP.  When I try to dial as a user I get the following 
error:

PORT: terminal Port set to "/dev/ttyS1".
DIP: tty: lock:(/var/lock/LCK..ttyS1).
Permission Denied
DIP: can't open - problem with locking ttyS1

I think error is with file permissions of some type.  Any help would be great.

Richard