Hi,
Solved this, i had a bad bundle prefix id in the Entitlements section. (i build with inhouse sdk for internal releases and standard sdk for appstore releases)
I found the issue looking at the ios console log with this tool (i'm on windows) : iPhone Configuration Utility 3.6.2 for Windows
The log told me that there was an issue with the "keychain-access-groups" value not valid for the current provisionning profile.
I will actually invest a little time in writing build scripts, as the process of manually switching between dev/inhouse/appstore releases is not error proof...
Eric