Help with raid and windows

[Michael Armida <michael@frood.org>]

I'm trying to set up a dual-boot machine with four identical SATA 
drives.  sda and sdb are controlled by the motherboard's nvidia raid 
controller; Windows Vista runs on these and I try to stay out of it's way.

Heeding the docs, I opted to use md to make sdc and sdd into a raid for 
debian.  When I run the installer, I choose the following layout:

- sdc1 and sdd1 are 255mb
- sdc2 and sdd2 are the rest of the drive
- sdc1 and sdd1 are made into raid_md0, which is ext3 for /boot
- sdc2 and sdd2 are the second raid partion, which is setup as LVM for 
everything else (guided partitioning default)

When I do this, sdc1 and sdd1 partition and setup fine, but the LVM 
partition generates an invalid arg error and the installer can't continue.

Questions:

1) is this a bad layout design?
2) should sdc1 and sdd1 not be md'd, but instead be regular ext3?  Some 
older docs read that GRUB can't handle md, some say it only can't handle 
LVM.  Which is currently correct?
3) how do I get past the "invalid argument" error?
4) where does GRUB go, once I'm ready to install?  Can it go on sdc/sdd, 
and not on sda/sdb, if I use the bootable flag on those drives and then 
jump over via boot menu items to Windows?

Thanks for your help or pointers or documentation RTFMs,
Michael