Yes, even that. Again, as Dan said - Cydia is being hammered ... still. All you can do it wait and keep trying.
The biggest thing to do is to go to the Changes tab in Cydia and hit the Refresh button on the upper left. That'll make sure that you get the full package download. Once it loads (and finishes with no errors), then your next best bet is to try to get tweaks one at a time.
I've noticed that if I try to do too much as once - which, for now, is to do more than one thing - will cause the errors.
We are probably talking about thousands of people, or more, who are hitting those servers. It's just going to take some time for it to settle down.
Marilyn