[imp] Login slow with one user, but not with others

[carlos maca]

hi, im using those version:

   - Horde: 3.1.1
   - Imp: H3 (4.1.2)
   - Ingo: H3 (1.1.1)
   <http://correio.unir.br/webmail/horde/ingo/test.php>
   - Passwd: H3 (3.0)
   - Turba: H3 (2.1.2)

and i experienced these 2 days ago, i have a user that is getting a slow
login, but all the others users have normal login, i do some tests, and i
login at the same time with X login and his login, and the X login get on
normal, but his login still getting slow.

Can anyone help me with this problem,
thnks carlos.