I use Firefox (3.6.13) as my default browser and I almost always have problems with the rendering of maps on openstreetmap.org. Specifically if I zoom in some tiles are not displayed (randomly), zooming out and in sometimes fixes the problems (as if the tiles were reloaded).
I do not have this problem on either IE or Chrome, installed on the same computer.
I have this problem on multiple computers (all running Windows 7) on FF (and not on the other browsers).
I have this problem on different networks (fast or slow access to Internet, with proxies or without).
It looks to me as if there was a cache problem on Firefox as the tests above seem to dismiss network issues. The missing portions are not stuck in download (FF claims that the page is “Done”). A refresh (F5) sometimes (but not always) fixes the problem for some time)
Has anybody noticed this? (I did not find any similar issues on Google at a first glance)
I am running W7 with FF 3.6.13 and have none of the issues described in WoJ’s note. Had some strange effects a few months ago with other maps (similar but not the same as described above), but F5 solved that (and since it disappeared).
Sounds like you might have blocked images from one of the tile servers? Its possible to do this accidentally in Firefox if you right click on the map, then click “block images from this server”. There are 3 different tile servers, so this would just block some of the map tiles, not all of them.
To check if you done this, click Tools menu, then “Options”. Pick the tab for “Content”. There should be a section for load images automatically, click on the button for exceptions and see if any osm sites are listed.
Thank you for the information - I checked and I do not have any kind of exceptions for images download.
The problem seems to be less visible for some time (just a few tiles are sometimes missing) so maybe that was some kind of computer voodoo. So I will hold on for some time and the issue may vanish completely