OL2k7 POP3/SMTP settings

Help please:

On my new computer running XP SP3, I am trying to configure Outlook 2007 to
collect and send my emails. It works perfectly with OE6 but the same
settings, either imported with the Import & Export wizard under File menu or
typed in manually or even copied from the information given by my ISP
(excactly similar to the OE6 settings) in OL 2007 return the following
message when testing the account settings:

Log onto incoming mail server (POP3): Cannot find the e-mail server. Verify the server information in your account properties.
Send test e-mail message: Cannot find the e-mail server. Verify the server information in your account properties.

Strangely, although I have access to the selection of POP3, IMAP or HTTP
account type when initially setting up the account, the selection box is
subsequently greyed out when returning to the settings after the test or when
trying to change / repair the account.

Under More Settings, I don't change anything to the defaults, which matches
the settings in OE6.

I have had Skype & Windows Live installed on the computer if that can have
any influence... but I uninstalled them to see if it would fix the problem:
no change!

Thanks for helping
--
av