Mates getting the same error today. Since a while, after reflashing with maemo flasher 3.5, my N900 worked well. Today I'm facing error 504 refreshing the 3 gulity repos maemo, extras-devel , and extra-testing. Any tip or solution?. I remember thart once I had this issue. Deleted the catalogues and created again, it worked. Non it's not so simple. Pls help