{"action":"opened","issue":{"url":"https://api.github.com/repos/aFarkas/lazysizes/issues/154","labels_url":"https://api.github.com/repos/aFarkas/lazysizes/issues/154/labels{/name}","comments_url":"https://api.github.com/repos/aFarkas/lazysizes/issues/154/comments","events_url":"https://api.github.com/repos/aFarkas/lazysizes/issues/154/events","html_url":"https://github.com/aFarkas/lazysizes/issues/154","id":105667075,"number":154,"title":"Firefox loads small version on first load","user":{"login":"sjelfull","id":10508,"avatar_url":"https://avatars.githubusercontent.com/u/10508?v=3","gravatar_id":"","url":"https://api.github.com/users/sjelfull","html_url":"https://github.com/sjelfull","followers_url":"https://api.github.com/users/sjelfull/followers","following_url":"https://api.github.com/users/sjelfull/following{/other_user}","gists_url":"https://api.github.com/users/sjelfull/gists{/gist_id}","starred_url":"https://api.github.com/users/sjelfull/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/sjelfull/subscriptions","organizations_url":"https://api.github.com/users/sjelfull/orgs","repos_url":"https://api.github.com/users/sjelfull/repos","events_url":"https://api.github.com/users/sjelfull/events{/privacy}","received_events_url":"https://api.github.com/users/sjelfull/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-09-09T19:22:51Z","updated_at":"2015-09-09T19:22:51Z","closed_at":null,"body":"I'm having a problem in Firefox 40, where the first image that shows have the small / mobile version loaded. When I replace the image with the next in the album, it shows the correct size.\r\n\r\nI'm using lazysizes 1.1.3 + respimg + custommedia plugin, as well as the <picture> syntax.\r\n\r\nThis is the custom media queries: \r\n\r\n    window.lazySizesConfig = window.lazySizesConfig || {};\r\n    window.lazySizesConfig.customMedia = {\r\n        '--small': '(max-width: 500px)',\r\n        '--smallish': '(min-width: 501px)',\r\n        '--until-medium': '(max-width: 749px)',\r\n        '--medium': '(min-width: 750px)',\r\n        '--large': '(min-width: 1400px)'\r\n    };\r\n\r\nThis is the picture element:\r\n\r\n```\r\n<picture>\r\n        <!--[if IE 9]><video style=\"display: none;\"><![endif]-->\r\n        <source\r\n        data-srcset=\"/imager/FOod/Untitled-01_e7529372b9e5cb61fb3d78cac01c270d.jpg\"\r\n        media=\"--until-medium\" />\r\n        <source\r\n        data-srcset=\"/imager/FOod/Untitled-01_97f7820f6ba9e9418a0a8856cbbba27d.jpg\"\r\n        media=\"--medium\" />\r\n        <!--[if IE 9]></video><![endif]-->\r\n        <img src=\"data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==\"\r\n    data-srcset=\"/imager/FOod/Untitled-01_e7529372b9e5cb61fb3d78cac01c270d.jpg\" data-sizes=\"auto\" class=\"lazyload\" width=\"1400\" height=\"933\" />\r\n</picture>\r\n```\r\n\r\nYou can see the test site here: http://tommy.neue.no\r\n\r\nDo you see anything wrong with my setup / syntax?"}}