Samba 3.0.14a from a Fedora Core 4, kernel 2.6.14 from Fedora, on a 64bit linux, 32bit W2k3 server
When using smbmount or mount -t smbfs on a linux to mount a windows 2003 share, the mounted dir hangs when the server reboots, and remains hung even when the server is back.
It seems you can only mount using smbfs from a w2k3 that ain't a Domain Controller (a DC required message signing, which is not supported by smbfs)
simple work around: use cifs instead of smbfs, remark: you cannot use: -o username=domain\\login but -o user=login,dom=domain
we don't maintain the smbfs kernel code. Sorry.
As you mention, the CIFS fs module is the best workaround.