IDE rescan => DISABLED, NO IRQ

I want to check my new kernel to see what changed about IDE
hotswapping, but I've got this message just after the rescan request:

Jan 23 15:54:19 WishMaster hdi: probing with STATUS(0x50) instead of
ALTSTATUS(0xff) 
Jan 23 15:54:19 WishMaster hdi: WDC WD153BA, ATA DISK drive 
Jan 23 15:54:19 WishMaster hdi: IRQ probe failed (0xfff83eb8) 
Jan 23 15:54:19 WishMaster hdj: probing with STATUS(0x50) instead of
ALTSTATUS(0xff) 
Jan 23 15:54:19 WishMaster hdj: ST320423A, ATA DISK drive 
Jan 23 15:54:19 WishMaster hdj: IRQ probe failed (0xfff83eb8) 
Jan 23 15:54:19 WishMaster ide4: DISABLED, NO IRQ 
Jan 23 15:54:40 WishMaster hdi: ERROR, PORTS ALREADY IN USE 
Jan 23 15:54:40 WishMaster hdj: ERROR, PORTS ALREADY IN USE 

the kernel say " ide4: ports already in use, skipping probe " and do
nothing if I try to rescan once again

I've 5 IDE controllers (three on board and a PCI card), interrupts are
assigned by the following order:
CPU0

  0:     448638    IO-APIC-edge  timer
  1:        518    IO-APIC-edge  keyboard
  2:          0          XT-PIC  cascade
 14:     123503    IO-APIC-edge  ide0
 15:      21569    IO-APIC-edge  ide1
 16:     245384   IO-APIC-level  ide2, ide3
 17:       9538   IO-APIC-level  aic7xxx
 18:    4319591   IO-APIC-level  ide4, eth0

kernel 2.4.18pre2, if you need other informations, tell me

  DaP