eBoot always works for me when needed, and if I have to decrypt, EETech works fine. I have never had any experience different with Windows 7 vs. Windows XP.
This may, however, have more to do with your EEPC policies. I have produc settings set to encrypt all drives vs the other options of boot only/all disks except boot. Also, in product settings, I have nothing checked under encryption providers; sepcifically, I believe the "Use windows system drive as boot disk" plays a role here.