So what happened to the unicorn blood curse?

[Deirdre F Woodward]

No: HPFGUIDX 83529

I just finished SS/PS (for the ???? time) and was struck by the whole
unicorn blood plot line.

First, Firenze tells Harry "It is a monstrous thing, to slay a unicorn [. .
.] The blood of a unicorn will keep you alive, even if you are an inch from
death, but at a terrible price.  You have slain something pure and
defenseless to save yourself and you will have but a half life, a cursed
life, from the moment the blood touches your lips." (PS, Brit ed., paper, pg
188).

Harry asks "But who'd be that desperate?" to which Firenze responds:  "Can
you think of nobody who has waited many years to return to power [. . .]?"
to which Harry replies "Do you mean [. . . ] that was Vol-" [he's then cut
off by Hermionie shouting to him]

Later in the book, Voldemort tells Harry, "Unicorn blood has strengthened
me, these past weeks  . . . you saw faithful Quirrell drinking it for me in
the forest" (PP, Brit ed., paper, pg 213).

So what gives?  Did Quirrell drink the blood?  Did Voldemort?  If Quirrell
was drinking the blood, how come we never saw the effects of "a half life, a
cursed life" in Quirrell?  He evidenced no cursed behavior throughout the
book, other than the long-time possession by Voldemort (I'm not drawing a
distinction between pre-inhabited Quirrell and inhabited Quirrell --
inhabited Quirrell is really no more cursed that pre-inhabited Quirrell.
Either way, once he's under the control of Voldemort, he's pretty much
cursed).

If Quirrell was drinking the blood to sustain Voldemort, does the curse
transfer to Voldemort?  If so, what are the consequences of that curse?

Any thoughts?

Deirdre

p.s. drove up to Canada to score the brit edition of the books -- I'm having
a blast reading them in "British."