Ok, forgive the stupid question...
But WHY, if the card has a lifetime warranty, do they care about a receipt or product registration? In my mind, a good hardware company backs up their product no matter where or when you bought it. The nominal cost to replace it is minor compared to the good will they earn.
I recently had to RMA some RAM. I had a pair of 1GB Wintec DDR2 memory sticks and I sent them back to them after filling out the online RMA form. A few weeks later, a brand new pair showed up in the mail, no hassle. Makes me want to always buy from them.
Treat the customer right and you'll have a customer for life. Give them the runaround, and you'll lose 10 customers.
BTW, this is why I buy EVERTHING from NewEgg. I have had a few returns to them due to DOAs in the past (actually got 2 ASUS motherboards in a row DOA, not NewEgg's fault, it happens), and they overnighted me replacements in advance for no extra charge, then upgraded my next order to overnight for free.
That is service, and I didn't get 1 bit of runaround, the guy on the phone was like, "don't worry, we'll take care of you".
Even if something is $5-10 cheaper elsewhere, I always buy from them because of this service.
The hassle isn't worth the savings, IMHO.
*soapbox mode off*