Drive letters won't "stick" after reboot

[McGraw]

I want my drive setup to be as follows:

C: Raptor partition 1
D: Raptor partition 2
E: Raid array
F: DVD
G: DVD Writer
H: Card reader
I: Card reader

If I set it up like this, on the next reboot the array is no longer E: It becomes I: which is no good to me at all.

So I tried this:

C:
D:
E:
P: DVD
Q: Writer
Y: Card reader
Z: Card reader

This set up retains the array as E: but the writer refuses to be anything other than F: and becomes F: after every reboot no matter what.

Does anyone have any clues or solutions?

Thanks a lot.

[McGraw]

By the way, I am doing this in XP, not x64 and I'm using disk management.