Alcor says:

"It is a well-established fact that long-term memories are encoded in durable physical and chemical changes."

• http://www.alcor.org/sciencefaq.htm

Usually the problem is not with freezing - but with thawing. Vitrification improves things further - but even without that an enormous quantity of information seems bound to be preserved. I don't think scepticism about this has much scientific basis. We know enough about the brain, and about freezing to see that a mountain of information will be preserved.

Also, check out the frozen frogs.