Recent calls SMS voicemail showing phone number instead of contact name iPhone

Hi guys,
I dont know why and how but somehow the automated sync on my iPhone 4 (4.2.1, no jailbreak, t-mobile Germany) between my adressbook an MobileMe stopped working.
So I turned off the sync in the mail preferences on my iPhone and deleted all my contacts.
After that I reactivated the sync and MobileMe send all my contacts back to my phone.
Perfect! ... I thought.
But now all my sms, voicemails and recent calls in are only showing up with the phone number and not with the actual contact name stored in my adressbook.
Incoming calls are showing up fine with the contact name.
When I call a contact directly from the adressbook it shows up with the name but when I dial a number manually the number shows up in my recent calls out.
I dont get it.
Does anyone have any idea whats going wrong and/or how to solve this?
Thank you!
iPhone 4 iOS 4