Some of my WinXP laptops, after they have been undocked and booted into cached credentials far from home, take forever to log in when they get home - as ANY user. The slowness happens just after the user enters their credentials, but before the user log in process dialog pops up. So they are left staring at a grayed out log in dialog for several minutes.

This is what I have found:
- Disconnected from the network, the computer logs in speedily.
- If the computer is logged into, then logged out, then logged into again without shutting down it functions normally.
- If the computer is dissociated from the domain and then rejoined, it works fine until the computer is undocked and booted. Then when it is returned it is slow again.
- No abnormal slowness is apparent after log in.
- The first DNS server is the DHCP server and the DC. There are 4 others, 2 of ours on a pretty fast connection and 2 are our ISP's.
- Disabling the wireless network adapter for boot solves the problem, but my users aren't comfortable disabling and re-enabling their W-NICs every time they leave the office.
- Reinstalling the wlan card driver fixed the problem temporarily.
- The presence of preferred wireless networks or not does not make a difference - they use hard wire exclusively while in the office, but there is a wireless network they should be configured to connect to manually only.
- All the machines are using the latest updates, including the DC (Win 2k3)
- the users have both mapped drives and mapped printers - which are valid and on the same set of switches.