Didn't you know that you need special software to access more than 4GB ? Your problem sounds clearly as if you tried without. Writing to DH1 overwrote the partition table and most of DH0. I doubt that there is anything you can do to recover. Now you have to start from the beginning again, i.e. initialize and partition the CF card, install the OS etc. But this time only create partitions of 4GB in total. Leave the upper half of the CF card empty until you installed the needed drivers.
More information there:
http://eab.abime.net/showthread.php?t=32256