Ralan's is reporting that Analog and Asimov's, both published by Dell Magazines, has editorial/submission address changes. The date on Ralan's for the tip was August 19th, so this is recent.
It's a funny thing. I've got files with submission guidelines for both from February 2003 -- and submitted to both in March 2003. Asimov's got updated, because of an editorial change. But the real thing is that I check guidelines websites on a regular basis -- less often from ones I submit to often -- and cruise Ralan's on a regular basis. Don't assume that addresses stay the same or that markets stay open. Recheck and verify.
By The Way
September is Ralan's donation drive month. If you use this resource, and you can spare some PayPal, send it his way. Because as bad as it is for markets to close, having resource sites close would make things really difficult.