Managing Remote XP Machines

I have an issue with some PCs in our environment, when I try to remotely management some XP SP2 PCs, I get an error message “Computer \\XXXXXXX cannot be managed because it is not running Windows NT. Would you like to manage it anyway?” It appears as though I can manage the computer. Any ideas as to why I get this message? I searches MS’s site can came up with nothing…

THANKS!