Sleep problem

[gabiz_ro]

First a little description.
I'm talking about a Dell laptop (E1705) with some mods.
Internal SATA port (ICH7-M,SATA I) works now at ESATA,for OS and other I have express card with 2 WD Scorpio black in RAID 0.
After many tries I'm able to boot from express card and all work fine.

With one exceptions,I have sleep problems.Resuming from sleep was in fact a cold boot.Under XP was a solution hibernate but now on windows 7 neither sleep or hibernation works.

For some testing I have switched to original BIOS,then I see that:
-express card connected but no disk attached,only internal one (original configuration with expresscard connected),sleep function works fine.
-express card connected with disks attached,same original config and sleep was not working,resuming from sleep result a cold boot.

So in that case I eliminated problem can be from a BIOS mod.

Any idea how can I solve this problem?
Where to look,what to check?