Twitter card does not work anymore after a certain time

embedsys · 2013-12-30T16:31:04.000Z

Hi,

When I share my page on Twitter the card works as expected but after some time my cards are no more displayed
For example these tweets :

Embedded Systems Weekly #10 is available online. Check it out! j.mp/1ahrqnH

You could have missed this weekend release of Embedded Systems Weekly Issue #8 j.mp/1hbYcvo (RT are welcome)

Is there something wrong with the way I provide meta data or anything else?

Thank you for your help

PS : You could not that @nytimes tweets with cards have the same problem https://twitter.com/nytimes/status/417690018703220736

rchoi · 2014-01-03T17:13:56.000Z

embedsys · 2014-01-17T10:35:16.000Z

Sometimes it works, often it does not work. Do you know if there is any problem times to times?