ntlmv2 not working on sparc64 linux

I maintain a custom linux distro to distribute one of our products.

On our x86 build, kernel 2.6.27, mount-cifs 3.0.28, this works:

mount -t cifs //server/path -o username=un,domain=d,sec=ntlmv2

On our sparc64 build, kernel 2.6.28, mount-cifs 3.0.30, the same command (to 
the same windows host) produces:

Mount error 13 = Permission Denied

Both kernels show ntlmv2 support:

# cat /proc/fs/cifs/SecurityFlags
0x7


Interestingly, if on the sparc64 box I change it to only use ntlm (v1), it 
works. Unfortunately, one of our clients is moving away from v1, so we need to 
figure out why it's failing with v2.

Any ideas on where else to look?


-- 
Nicholas Leippe