Comment 4 for bug 752012

I'm running Ubuntu Natty (up-to-date) and I experience exactly the same issue.
I have to unmount my cifs share before suspend otherwise I get:
[ 3026.159509] Freezing of tasks failed after 20.01 seconds (1 tasks refusing to freeze, wq_busy=0):
[ 3026.159542] ksysguardd D 8c443c58 0 1703 1701 0x00800004
[ 3026.159549] ee6bddf4 00200086 ee6bdde4 8c443c58 00200246 00000023 ee5b41ac c1877680
[ 3026.159559] 91088855 000002bb ee5b41a8 c1877680 c1877680 f7847680 ee5b3f20 f74d0000
[ 3026.159568] ee6bde14 ffffffa8 ee6bde0c fa222e47 00000001 00000048 00000010 ee6bddc8
[ 3026.159577] Call Trace:
[ 3026.159597] [<fa222e47>] ? smb_sendv+0xe7/0x310 [cifs]
[ 3026.159607] [<c1035908>] ? default_spin_lock_flags+0x8/0x10
[ 3026.159617] [<c15319df>] ? _raw_spin_lock_irqsave+0x2f/0x50
[ 3026.159626] [<c1076ed8>] ? prepare_to_wait+0x48/0x70
[ 3026.159636] [<fa22314f>] wait_for_response.clone.1+0x6f/0xb0 [cifs]
[ 3026.159638] [<c1076c70>] ? autoremove_wake_function+0x0/0x50
[ 3026.159644] [<fa223dbd>] SendReceive+0x17d/0x370 [cifs]
[ 3026.159647] [<fa206d6e>] ? smb_init+0x6e/0x90 [cifs]
[ 3026.159652] [<fa20d1ae>] CIFSSMBQFSPosixInfo+0xee/0x230 [cifs]
[ 3026.159656] [<fa2058e3>] cifs_statfs+0xd3/0x150 [cifs]
[ 3026.159661] [<c114cb58>] ? mntput+0x18/0x30
[ 3026.159664] [<c113b5ea>] ? path_put+0x1a/0x20
[ 3026.159667] [<c1158b95>] statfs_by_dentry+0x65/0x90
[ 3026.159669] [<c1158be2>] vfs_statfs+0x22/0xc0
[ 3026.159671] [<c1158ca0>] do_statfs64+0x20/0x40
[ 3026.159674] [<c1158ec0>] sys_statfs64+0x50/0x80
[ 3026.159677] [<c100ab5f>] sysenter_do_call+0x12/0x28

Here is the mount entry:
//192.168.1.2/encrypted/ on /home/chris/hydro type cifs (rw,mand,nosuid,nodev,user=chris)

It is mounted with "user" option so that a regular user can unmount it without sudo. Unfortunately, this does not help.
My cifs share uses authentication, I don't know if it matters.

The behavior is consistent, suspend fails every time if the cifs share is mounted. I'll be happy to provide additional information if you need.