Yes, dirk. First welcome to the Forums.
There could be any one of several reasons... the most common of which is that one of your outlook records is corrupt OR doesn't contain data in either the First, Last or Company name field. One of those fields MUST be populated for the BlackBerry to index the record, and it won't import a record otherwise, hence the error.
More tips here: Errors syncing the BB with Desktop Manager - BlackBerryFAQ.com