[imp] IMP Identity is distributed to all users

[Pascal Robert]

Hi,

we just upgraded a Webmail system from Horde2/IMP 3 to Horde 3.1.4/ 
IMP 4.1.4, and we have a strange problem : when one user is editing  
is default profile, the changes are distributed to all users !  For  
example, if User A change his signature and save it, when User B  
compose a new email, he will see User A's signature :-(

Deleting all data from the horde_% tables don't fix the problem.