hotplug doesn't work on kernels >= 2.6.7

[Angelo]

Hi all.

I've fedora core 2 installed on my desktop and laptop.

I've noticed that with kernels (smp and non) >= 2.6.7 hotplugging 
(linux-hotplug.sf.net) doesn't work at all on my desktop, on the laptop 
works fine.

I mean that if i plug-in a usb device with the successfully booted 
machine it simply doesn't recognize at all that i've plugged in the device:
- NO /var/log/messages after i plug-in
- NO /sbin/hotplug call
- NO debug messages on a full kernel log
- NO strange messages in the dmesg (when booting)
- NO new device using /sbin/lsusb

Simply nothing strange.

Cold-plugging works fine, I mean plug-in the device and the boot the 
machine.

Is there some way to diagnosticate better the issue and report here or 
in bugzilla the results ?

HW info of the victim box:
- P4P800 Deluxe mobo
- Pentium 4 2.8 HT
- 1GB of DDR RAM

usb devices tried:
- pendrive
- hp printer
- usb mouse

All these devices work fine with kernel-2.6.6-1.435.2.3

Regards,
Angelo