For Crying Out Loud

Okay, does anyone have any words of wisdom to give Husband and I, because we are, or at least I am, at our wits end. We have been blessed with a very handsome, very fun baby (during the day) who then turns into a crying, screaming beast at night. We first tired the "attachment parenting" technique, going to Gumba every time he cried or waked up, giving pacifiers, nursing him. When this failed to solve the problem of him waking up every hour or two, we finally succumbed to the holy grail method that EVERYONE boasts about, the "cry it out" (CIO) technique. We've been at it now for four weeks, and he still has nights (more then less) where we are forced to let him cry anywhere between 20-90 min at night. I asked the pediatrician why he hasn't learned yet, mind you everyone says that you'll have three difficult nights, and she couldn't come up with why he's still crying for so long. I do still nurse him during the night. I figure we either have an incredibly stubborn child, or a dumb one. At this juncture I'm not sure which is best. So, I've decided that my maximum time limit for letting him cry before we soothe him is 40 minutes. Does anyone out there have a similar experience, or have some advice to give us? We could sure use it.