Did you connect the workstation to the domain using the //domainname/connectcomputer via internet explorer or did you use the "system properties - computer name tab" option ?
Also what service pack are you using on the server ?
Connecting via your browser does way more than manually connecting the computer to the network through the control panel:
First, there's the whole server site setup that enables and configures
dependencies and configuration options that connectcomputer funcionality
1. Checks Client OS and takes appropriate path (ATAP)
2. Causes an activex control to become available.
3. Determines whether the computer is or is not a member of the domain, and
is or is not a DC or SBS server, (ATAP)
4. Tests resolution to the SBS server (ATAP)
5. Checks for multiple non VPN network connections (ATAP)
6. Checks account permissions, allowed to join computer to domain?
7. Assigns users, and migrates local profile(s), if they exist, to domain
profile (SID mapping)
8. Assigns requered local permissions to domain user account.
9. Provides selection of computer name from list, automatically if there is
one-to-one mapping of user/computer on the SBS.
10. Joins the domain (creating a temp user account for autologon to ease the
process) - including getting the client computer in the correct AD OU so the
GP applies correctly.
11. Sets some runonce reg keys to clean up after the above process.
12. After required input is provided, steps through the above process,
including automatic restarts as required.
13. Now we are into Application Deployment
This is seen on the workstation as the Client Setup Wizard, which is
automatic on login after the above 12 main steps are complete.
14. The list of configurations made after Application deployment:
My network places
ActiveSync (special, just for SBS and mobility devices)
Additional global settings:
DNS Timeout Value
Deleted Item Recovey
Remote Desktop permissions
Disable getting started screen (annoying XP thing)
(used to turn off ICF, but now handled by GP (xp firewall settings))
Disables network bridging