Are you changing the pad out quickly? That's the only other thing I can think of after reading your post. Well, that, and while you want the pad clean, you don't want it TOO clean. I think smelling urine stimulates dogs to pee, males at least. So make sure to blot one corner of the pad with the urine from the used pad.
Thor had absolutely no idea what the pads were for when we started. I basically did what you describe in your last paragraph - I put him in the crate, took him out every hour, and put him on the pad. I did not let him move off the pad. If he sat or laid down, I took that as a sign he wasn't going to potty, and put him back in the crate.
We had two marathon sessions that lasted over 24 hours where Thor would not go. He also cried about half the time he was in the crate. Once he got it, he got it, though. Now he's using his pad a dozen times a day.
It is a little trickier when they pee and don't poop. I had a couple experiences in the morning where he peed, and then I left him for a few minutes, only to come back to a pile of poop somewhere other than the pad. It seems like he prefers to do it when I'm not around.
Basically, I let him out of the crate and reward him for peeing. However, if he doesn't poop, I still keep a close eye on him. I'm only totally confident for two hours after he's done #1 & 2.
On the plus side, it is harder to do a "lightning dump". These little stinkers can pee in the blink of an eye, but you get more of a warning and opportunity to put them on the pad for poop.