Problem with some images in map's balloons

[MrPippoTN]

Please have a look at this link: http://www.meteotrentinoaltoadige.it/webcam-associative

There's a Phoca Map collecting webcams for weather watchers. Here's the problem.

Sometimes the image in the balloon works...



sometimes doesn't.



WHY???

Please have a look at the map and try to click on the images... And let me know what do you think.

Thank you in advance,
Filippo