Share email folder doesn't share subfolders

Hello all,

We've migrated from 7.1.2 on Debian 5 to 8.0.0 on Ubuntu 12.04 LTS.

All shared mail folders are present, but without subfolders. If we want to delete and recreate shares, the problem still present. But if we create new accounts and we share folder with subfolders, the problem is not present.

This is only with migrated accounts.

Any ideas ?

Thanks in advance !