Work around recently-released-dataset issues

Often we have issues where one IP address (the DNS resolves to 2 or more) will have a dataset and the other one won't yet. This causes "blah is not an available dataset" errors since predict.py thinks it's OK to use a recent one, and then by chance we end up talking to a server on a later request that doesn't have it.

This should hopefully work around the problem... in fact, I have not received a "predictor is broken" email in 3 days now (!).