Problem with superblock when creating a software raid 5 array
 

I am running SME Server 7 Final. It is installed on a 80gig (hda) hard drive. I have added 5 x 250gb western digital hard drives (hd[cefgh]) and created a software raid 5 array with the following command:

mdadm -C /dev/md3 -l 5 -n 5 -c 256 /dev/hd[cefgh]

Success so far, checking in /proc/mdstat i can see the array rebuilding.
when i issue the following command:

mdadm -E /dev/hd[cefgh]

it reveals the superblock and I can see that the checksum is correct for all drives. Even after rebooting the system the array comes up perfectly fine and the checksums stays intact.

Now the problem is as follows:
After I created a file system with the following command:

mke2fs /dev/md3 –b 4096 –R stride=64 –j

the checksum if hde and hdf becomes invalid. And when I reboot the system the array fails to start because of 2 missing members (hde and hdf). If I stop the array and forcefully recreate it, all the data is still intact but the checksums on those 2 drives stays invalid and therefore after a reboot the array is down again.

Any ideas?