Problem with Software Raid 5

[muli]

Hi!

I have a problem trying to run a Linux Software Raid 5 on a system running Gentoo Linux..

I use following setup:
a epox 8k9a3+ mainboard with a Highpoint Hpt374 Controller onboard
3 seagate barracudas with 120 GB (2 7200.7 and one barracuda V) connected to the hpt374
1 seagate cuda V 80GB as system disk connected to a normal ide port

in the kernel i have compiled support for the HPT36X/HPT37X chipset and raid support for levels 0,1,5

now whenever i try to create a raid 5 array with the 3 disks, the sync process starts (can be seen in /proc/mdstat ) , i can see the array working like it should
but after a random time the system simply hangs up, without an error or whatever, i can just do a reset to get the system back to life

i already searched the forum about the issue, and things i´ve found and tried are:
* changed the ide cables
* tried different kernel versions (vanilla-2.4.21,vanilla-2.4.20, ac-sources-r2 and -r4)
* disabled acpi

but nothing worked... the system always crashes when syncing the array...

raid 0 + 1 work without any problems ( i have a raid 1 running now ), also are the disks itself ok and can be used without a raid...

what could be the reason for the problems with the raid 5 ??

any suggestions ??

Many thx in advance,
cheers
muli