briefcase and permissions

I've succesfully migrated a domain with about 50 accounts, but now I'm facing a little problem with signatures.

Users use a custom signature with a link to an image hosted on a public directory from his own briefcase.

after migration signatures still points to old server (URL changed).

I detected two problems:

1 - migration scripts don't change briefcase URLs. for examples this:

should be this:

2 - briefcase permissions are changed. each users has a directory with Public permissions (anyone can acces for reading). but after migration those permissions are revoked.

are those known problems?