[Samba] Home drive and logon scripts intermitently not applied

[George]

Hi folks,

This problem has been driving me nuts for the last 3 years... Now I am
running Samba 4.0.9 but the very same was happening before the
migration to AD, with Samba 3.x. Most clients are running WinXP SP3
with all updates.

The problem is that both the logon script and home drive defined on
the "Profile" tab on the AD Users and Computers MMC, *RANDOMLY* and
*INTERMITENTLY* does not run. This happpens randonmly on any PC of the
50 I have here, regardless of the software they have installed.

Most times this fails immediately after the PC is turned on. The user
is able to login properly but no logon scripts or home drive. If the
user then logs off and logs in again, then it always works. Also, if I
let the PC sit on the "Press Crtl-Alt-Del" screen for several minutes
and then logon, most times the issue does not occur. I know that
probably this is not a Samba issue, but hopefully you can help. I have
read thousands of posts about this problem, but couldn't find a
solution or at least the cause of the issue.

(SOME) THINGS I HAVE TRIED, AND DIDN'T WORK:
* GPO for waiting for the network to be ready prior to processing
scripts (this was the obvious answer, but didn't solve the problem)
* GPO for disabling low link detection at computer and user level
(both the one that disables the detection and the one on which you set
the threshold to "0")
* Disabled domain cached logons
* Manually enabled NetBIOS on the TCP/IP properties
* Lots of different combinations of the previous and other GPOs

Here there is an USERENV log from today (I am not able to identify the problem):
http://pastebin.com/A9LkjznZ - First logon after turning the PC on,
script not executed and home drive not connected
http://pastebin.com/EQV0cPVy - Logoff and logon again after previous
attempt. Script was executed successfully and home drive was
connected.

Any ideas?

Thanks a lot,

George