something to try

[ffoss]

I have been beating my head out for several weeks and just got my xp
machine to log into my domain!   

Look at your passwd file and smbpasswd. The user ids of course must
match. I also found that they need to be in the 100 range. Redhat has
modified their adduser command to work like this. The -r creates a
machine account, with the user id the first available id > 100 instead
of the usual user Id > 500

adduser -r -s /dev/null -d /dev/null machine-name$

I haven't taken the time to re try with a user ID > 500 etc but this was
the last change I made before it started working. I hope this helps
someone. 
I ASSuME that none-redhat users can create the password entry normally
and manually change the 5xx to a free 1xx number

Btw I created a script addsmbmachine containing one line:

adduser -r -s /dev/null -d /dev/null $1\$

the \ of course escapes the $ so it will be taken literally

Hope this helps one or two out there

fred