You are running EasyBCD in W7
W7 sees your XPs as D and I
That does not mean that's how they see themselves.
Disk letters are just virtual labels in the registry of the running system.
There are no disk letters in the BCD, EasyBCD is just telling you how the system you are running on sees them, by translating the UIDs.
Either delete the XP entry from the BCD and add it again letting EasyBCD auto-configure (that will give you a second NTLDR menu after you select XP from the bootmgr menu, and you can select the desired XP from that)
Or, delete the XP entry and add 2 manual entries to the BCD for XP on the drive letters as W7 sees them. ( that will give you a single bootmgr menu with 3 choices for W7 and either XP)
see the wiki for details of how EasyBCD achieves this feat, impossible by any other means.
There's no need to manually edit boot.ini if you're using EasyBCD 2.0