Bug#373145: This seems to be resolved
I just tested the etch installer rc1 on MS Virtual PC, with two
virtual hard disks, partitioned as:
hda1, hdb1 = 64MB swap
hda2, hdb2 = 1GB RAID
The partitioner is still awesome :-) and GRUB is now properly
configured: root (hd0,1)
So at least I can say that the installer seems to work properly with
clean hard disks. Also, I no longer see the "device is already open"
error messages that I mentioned previously.
I doubt that I can reproduce the conditions that originally resulted
in this bug report.