Multiple Echo Layla Troubles

I Have a Small recording studio With 2 x Layla24 units and a Layla20 Unit as
Audio intefaces (recorders)

I've just Changed My PC for more performance and I have been having problems
since.

I went from a win98 OS to a WinXP pro . I use Cubase VST32 and Cubase SX for
Multitracking .

Here are my Problems since:

-The Layla20 outputs are totally dead.
-My computer looses communication with all my Units and my PC freezes
-Every time I've Restarted my Computer from my Start menu ,It gives me A
Blue Screen After it saves my setting


If anyone has Any Idea Why It does so , please Contact me
And Please keep in mind that I'm not an Idiot , So no Obvious Answers

Here's What I did to Troubleshoot:
-Got the most recent driver
-Tried every card one by one
-Switched Pci slots
-unplugged all the secondary hardware and kept the system bare
-checked all the units and cards on my old system (win98)
-switched master and slaves with Word clock
-fiddled with audio buffers and format

Old machine:
P3 1Ghz
Asus Motherboard
512 Meg Ram
Win98
ATI All in wonder 8500DV


New Machine
P4 2.4 Ghz
Asus P4C800 Deluxe
1Gig Ram
2x WD 80gig
Baracuda 30 gig
Scsi Seagate 20 gig
Floppy
Generic CDrom 52x
Scsi Yamaha CRW 2100S
Scsi Amaha CRW 8424S
Domex SCSI card
2x Layla24
Layla20
Matrox G550 Dual
550w Antec true power
Lots of ventilation


THX