How did you try to "force" all contacts to be sorted by last name?
The way it works is Outlook has a "Full Name" field as well as a "File as" field for each contact. This allows you to sort the contacts one way but display them another way.
When you sync the contacts to the phone, the sync program looks at the "Full Name" field in Outlook and sends that to the phone along with the other info (phone numbers).
So however you have the name listed in the "Full Name" field in outlooks is how it will show up and be sorted on your phone. Make sure you have all of those names in setup consistently. And keep in mind that this phone is not a PDA and has very limited contacts features.
