If you want to keep the Windows 7 installation on the SSD, you can mark it Active then with the other HD unplugged boot the Windows 7 DVD to run Startup Repair up to 3 separate times to write the boot files to the SSD Windows 7 which were placed on XP Active partition since it was not unplugged during install.
This method will allow you to boot the HD's independently via the BIOS, which keeps each free to come and go as you please. Set SSD first to boot after DVD, then boot the SATA Windows 7 using the one-time BIOS Boot Menu key given on first screen when you boot.