XP slow logon

I’ve got a problem that has got me completely baffled. I’ve got a Windows XP Pro machines connecting to a Windows NT domain server. They all logon, but it takes probably 2 full minutes to get to the desktop after the logon screen. It sits at “Applying your personal settings” screen for what seems like forever and then finally gets to the desktop. I’ve checked the firewall settings for the network connection and it is disabled. I’ve reconfigured the server back to all default settings on group policy and the like. Nothing seems to help. Anyone else seen this or experienced this? Thanks for any info.