Running Zimbra 7.1.3 and a windows phone 7.5 (mango)

Connected the phone to zimbra using activesync.

No , my name in Zimbra contains swedish characters and sending a mail using webinterface to myselfe results in a From: line that looks like this:
From: =?utf-8?Q?Bj=C3=B6rn?= XXX <bjorn.XXX@XXX.se>

If i look at this in Zimbra webinterface it looks fine , but if i look at this on my phone the =?utf-8 part is not decoded.

Sending the same mail to gmail or hotmail and the From decodes fine.

Looking at this on my Android 3.2 or on my iphone 5.0 connected using active sync it looks just fine.

So, anyone else have this problem? and how can i solve it?
Since hotmail is using activesync too and there it works there must be something in the zimbra side...