Since the water isn't dripping on anything on your home's structure, or pudding in anyway that could cause damage, then I think the water is not a problem. Some things to consider: You have vapor barrier over the whole floor? Is it a dirt floor? That is one way to reduce the humidity in the crawlspace... cover the floor, from wall to wall with a 6 mil poly vapor barrier (I am thinking you have that?) Also, make sure the vapor barrier is as tight as it can be on the duct... or the moisture will wet the insulation rendering ineffective. Otherwise... if the humidity is high enough... and the duct temp below the dew point... It will condense... nothing you can do but add more insulation. You can run a dehumidifier in the crawlspace to lower the humidity down there.

Bentonthebest