can we still sort by zip code in items for sale?

Yes. My system is not accessible either. I have emailed about the problem.
The best I can figure is that they're still in Beta and working the bugs out. And they're limiting any contact so to have complete control.
I don't like the change, but it is what it is.

I agree with Theo. I miss e-mailing members directly as well. I've met some really cool and helpful people here through that function. I can understand A'gon's wanting to stop the sideline wheeling and dealing but there must have been another way.

IMO, they should have just raised the price to post an ad based on the dollar value of the ad. They would have received their cut up front and not had all the hassle of worrying about people side-stepping the fee. Then it wouldn't matter if we talk to each other - too easy. I suspect what happened is they thought raising the fee too much would start an uproar so they decided to hit everyone on the backside because it wasn't so obvious. Unintended consequences.

typing in the zip code in the search box does nothing.

The Google search box, not Audiogon search box. Just open a new tab, paste the zip in the Google search box, hit go and the search results generally show the city without even having to open them. Once you have your city, close the new tab, it only takes a few seconds.