We have to do some maintenance work in Panoramio for 48 hours starting on Sunday September 20th around 12:00 GMT (13:00 Continental Europe, 05:00, San Francisco, 21:00 Beijing).
During this period of time you will not be able to sign-in in Panoramio. This means that anything that requires to sign-in (upload photos, add a comment, delete photos, manage tags, etc) will be disabled. When you click over any of those features you will get a page with the message "Sorry, this page will not be available for the next 48 hours". Also it wouldn't be possible to add posts to the forum nor comments to Panoramio's blog. Everything else in Panoramio should work normally; photo browsing, map page, personal pages, etc.
After approximately 48 hours (Tuesday September 22nd at 12:00 GMT) everything should be back to normality with some minor changes that I have explained in this post.
Sorry for the trouble, but it is something we had to do unavoidably. I am looking forward to see your newest photos on Tuesday.