To quote my reply to an email from Kathy A.:
"They blew out the vein on my left arm (after I'd been on the machine for about a half-hour) and then, when they moved over to the other arm, I started feeling woozy. Which, it turns out, is because my left arm was still bleeding pretty heavily.I didn't give enough for them to use any of and I won't be able to donate again until December 5. I am disappointed."
And I got a lovely elbow bruise as a bonus! However, I'm ready to try again in December. Maybe next time, they'll listen to me when I tell them I don't think the needle is in right.