Thanks for the reply.
Had a good discussion with lordvader129, so I'm updated on the need for 32k clusters, and have formatted my drive accordingly. The problem is: my current X2 4981.06 bios have apparently the "Ignore Harddrive Partition table" option checked(activated). This means that partition information, including information on 32k clusters, is being ignored. Thats why I need a bios which enables me to edit/correct/control the Ignore Hard Drive Partitions" settings and LBA48 support.
I have formatted my drive with 32k clusters, but still get corruption when exceeding 250GB on my 400GB drive.
As you suggest, I could go for a x2 4981.67 bios, but as long as this also has the "Ignore Harddrive Partition table" activated, I will not be able to custom make my partitions since the partition information will not be read. The result (as far as I know) will be a 137GB F: and a 250GB G:, and approx. 20GB missing. Or am I completly mistaken here?
So, as I see it, my option is to either scale back to a 250GB drive, and be satisfied with that (and save some money), or flash my TSOP with another bios to utilize my 400GB drive. But which bios to use? The only one I've seen that allows changes to the LBA48 AND "Ignore Harddrive Partition table" options are M7 using XBtool. I've been very satisfied with my current 4981.06, and never had any problems with this. Can I expect the same from M7? What about 4983.06? I am unable to edit this bios - but does it have the "Ignore Harddrive Partition table" option enabled or disabled as default (when getting it from xbins).
Many questions, I know.
But I'm quite stumped here, and hope someone can help me out.