Gretchen and Orchid, mine came out the same way when I tried it, last year...
I just figured maybe the onions were too watery, and I really don't understand why they would caramelize anyway, from a technical point of view.
Crockpots are covered, and it seems to me they would just steam, and not brown. To brown, they would need air, right? Like in an open saucepan?
Anyone know the science of this? Where is Harimad when you need her! ;o)