Drive letter assignments

I have the following disk setup:
Partition 1, primary and active, 1GB, contains only the boot files and a few
utilities
Partition 2, logical, 40GB, contains XP SP2
Partition 3, logical, 40GB, contains Vista build 5308
Partition 4, logical, 39GB, contains common data

I (re)installed Vista by booting from the DVD, not from within XP.

When I boot to XP, the drive letters are assigned as follows:
P1 is C:
P2 is D:
P3 is E:
P4 is F:

When I boot to Vista, this is what I get:
P1 is D:
P2 is E:
P3 is C:
P4 is F:

This is rather confusing. At worst I might have expected the letters for P2
and P3 to be swapped, but the boot partition should remain C: in all cases,
IMO. Better yet, the setup process should allow chosing the letter
assignments from the word go.
--
Pierre Szwarc
Paris, France
PGP key ID 0x75B5779B
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