Why is water pooling on top of the soil of my indoor palm trees?

This is my question, and I want to elaborate. I have a group of about 7 indoor palms in a large pot, and suddenly this winter it is not taking water like it used to. In the past, I had typically watered weekly with about a 1.5 gallons of water, and it was doing beautifully. Now, with even less water, the water pools on top of the soil. Note that the water isn't running through the soil because it is so dry that it can't absorb so it leaks out the bottom of the pot. It pools on top, which is just odd. Any ideas are greatly appreciated.