What’s Going On With User Interface To Del.icio.us?

I use del.icio.us as a filing system for things on the web. Today, the user interface for del.icio.us looks like the equiavlent to finding one’s file cabinet with no file folders and all the individual papers stacked in chronological order (but with little Post-It notes saying which file folder the paper belonged in). How useful is this latter filing system to me? Today I had to find something that I filed in del.icio.us, and now I can’t find it. I know that del.icio.us is a popularity tool to some, a wisdom of crowds things for others, but for me a big portion of del.icio.us is in its use as a productivity and organization tool. I even started to train some workers using del.icio.us (for knowledge sharing of things on the net). Is the definition of the tool changing? Or is it just a service issue or temporary bug? Or is it just a user interface change that I don’t understand?