.JPG Expiry Dates?

[gtd2000]

I'm sure most of you have a few chat buddies online via the various messengers etc.

I've noticed that I sometimes receive images from these chat buddies which at some point in time is no longer viewable. Thats is to say that the images were viewable then for some unknown reason become un-viewable.
I just have the .jpg icon when in the thumbnail view mode and the file name.

Is there some sort of encoding in .jpg files that puts an expiry date on the images?

Or....I'm i just going nuts?

 

[Nohr]

Maybe your chat program deletes transferred files after they're so many days old.

 

[gtd2000]

I suppose that is possible but other files that I receive are fine.
I've not set anything to delete files either?

It's mainly from internet only contacts that this happens. It is not something that happens all the time - just occasionally.

When I look at the properties of the files, the size is 0kb

Something causes the files size to be set to zero then it can't be opened.