I have an old Nokia phone as my private phone, but we don't use Nokia at work. The work phones are all of another brand, with a few exceptions. Those exception Nokia are mostly a pain, which is the main reason we don't all use them.

To make it short: It isn't possible to just dump the whole corp. contacts list (as a vcard file) into Nokia phones, they can only take contacts one-by-one, which is simply not an option for a corporation. Fix that, Nokia, and you'll have lots of enterprise customers. Even better, support categories (category=vcard file name, as on E.g. Palm), so that it's possible to scratch&reload by category and people don't have to suffer losing their private contacts.