Vista share authentication issues

[jling at SonicWALL.com]

Trying to browse to a share on a Vista (Ultimate) machine and I keep
getting asked to authenticate.  Packet capture on the Vista machine
shows anonymous request then access denied.  No other packets it seems
or attempts to authenticate with NTLM or other schemes.  

Packet capture on a Windows XP SP2 machine that is working for me shows
NTLMSSP_NEGOTIATE and NTLMSSP_CHALLENGE followed by NTLMSSP_AUTH, user:
myuser then at the end I also see the anonymous request with access
denied, yet I stiill gain access to the share.

Is there something I'm doing wrong with using the library?  

The call is 

smbc_init(auth_fn, 0); 

smbc_opendir(smbcmd); 

 

TIA for any help.