SMB works, CIFS doesn't.

Hello all,

I'm trying to mount a Windows XP share on my FC3/i386 machine.
As I need to move big files (>4GB), I'm trying to use CIFS (instead of
SMBFS, which AFAIK is limited to 2GB [32bit signed]).
However, while smbfs works just fine, CIFS mount fails on error -5 (-
EIO), dmesg entry: "CIFS VFS: cifs_mount failed w/return code = -5".

SMB options:
//gilboa-work-win/Backup /mnt/backup smb
noauto,user,username=gilboad,fmask=0666,dmask=0777 0 0

CIFS options:
//gilboa-work-win/Backup /mnt/backup_cifs cifs
noauto,user,user=gilboad,file_mode=0666,dir_mode=0777 0 0

Kernel:
2.6.12-1.1381_FC3smp

Any ideas?
Gilboa