Hello Tom, welcome to NST.
I don't know why EasyBCD 2.0 Beta (assumedly Build 63) is crashing like that on you, but I'm sure the developer ("Computer Guru") will be along shortly to help answer that question. In the meantime, just copy over the files BOOT.INI, NTLDR, and NTDETECT.COM into the root of your Vista partition (because it is "system" and is where you need to put the boot files of all systems when using the Vista bootloader as the primary one). Then adjust the rdisk() and partition() values in both lines in your boot.ini file, to reflect the currect location of your XP partition, in relation to the BIOS boot sequence, and MBR partition table.
And you will have a dual-boot.