Outlook account defaults to 127.0.01

In Outlook 2000
Situation in Outlook 200 Accounts, POP3
The username connects, picks up email then defaults to 127.0.0.1 (Loopback address)
e.g. guy@members.v21.co collects email on V21.co.uk. Then username reverts to = 127.0.0.1
Reset, collectemail – then back to 127.0.01
Any Ideas?