Error when mounting samba on Sun NAS

I get the following error when I try to mount a samba on a Sun 5310 NAS.

Bad File Descriptor.

I use the command

SMBfsys &
mount_smb //netbios_name:ipaddress/tree /local_path

this mounts not a problem and i can even navigate through directories. however when i try to copy, paste or edit anything in there it comes up with the error message.

I am using QNX4 with SMBfsys version 1.30I