Outlook Hangs when checking email addreses with directory service

[James Frayne]

I'm using Outlook 2000 service pack 3 in Internet Mail Only configuration

Outlook hangs about 75% of the time when looking up an e-mail address in the
university of bristol directory service
however outlook express can look up an address successfully in the directory
service 100% of the time and both outlook and outlook express
have the directory account settings exactly the same.

I would ask for help from the university's computing service but Outlook is
currently unsupported by them.

Any ideas why it hangs?

Thanks

James