XP slow start on linux host with sas controller

[badfiles]

When I switch IO controller to sas some machines take ~30 sec delay on boot.
For sas and sata IO controllers I always have 'host IO caching' unchecked.
I use Windows XP SP3 32 bit machines with all necessary drivers installed.
As a host system I use Ubuntu linux (64 bit).

Some machines start rapidly with active sas IO controller. All machines have the same driver and MS update setup.
Just adding an empty sas IO controller is sufficient to have a slow start on boot.
I am not able to find any difference inside between rapid and slow machines.

After a successful boot slow or rapid machine works just fine.

There are three logs attached: slow machine start with active sas IO controller, slow machine start with active sata IO controller, rapid machine start with active sas IO controller.

[squall leonhart]

I can reproduce this reliably, SAS controller must be enabled and have a driver installed
It will then delay boot with IDE, SCSI or SATA by sitting on the XP Loading screen for 20-40 seconds with the progress bar scrolling across with very minimal hdd activity on the host.

Disabling the driver in the guest and then rebooting will be fast again.
On the subject of disabling the driver, this device takes 30 seconds to disable/enable, and while enabled device manager will go non responsive for 30 seconds when 'scanning for hardware changes.'

LSI Logic SCSI controller and LSI Logic SAS controller use the same driver, yet this behaviour is only present on the SAS controller.