[imp] IMP identity problem

[Karolis Dautartas]

hi,

I am trying to remove multiple identities from IMP and just have one
identity per user.

I have set the following:
$_prefs['default_identity'] = array(
    'value' => 0,
    'locked' => true,
    'shared' => true,
    'type' => 'implicit'
);

And I deleted IMP and Horder preference records in LDAP database (I
keep preferences in LDAP). This works fine, and removes identity
selection from "Compose" and "settings" pages.

However after some time, multiple identities are magically re-enabled.
If I log out and then log in again, they dissapear again. But after
some time, they magically appear again.

This effect is also true for some other locked settings, like
language settings.

I am wondering what could be the problem.

Karolis