The public store access application has been broken for a few days, and it was a matter of sloppy testing on my part when I upgraded the app server from VW 7 to VW 7.1. In VW 7, the VisualWave namespace was imported into the Smalltalk namespace; in 7.1, that's no longer the case. The Postgres app is an old wave application, and a couple of methods - in particular, a method that was needed just to open the web page - could no longer "see" a class that was referenced.
That's fixed now, and things are back in business. I apologize for the inconvenience.