Tried all them. Left the Opera page alone for over an hour, but now it's suddenly there as intended without me doing anything.

It's almost as if Opera has suddenly become incredibly slow at allowing the change to be made, or a naughty pixie in the system only makes the change when I'm not looking. Maybe same delay occured with the P405 pic change yesterday .....

I guess you tried the various refresh method, i.e. F5 / Ctrl+F5 / Ctrl+R / clicking on the refresh icon...
Maybe they use some additional caching method

I use Opera, which is still showing the old P405 picture (night view of front). But have just opened the page in Mozilla and it shows the updated picture as I want it to appear (rear view with legible badge).

Weird ....

Someone else recently had problems refreshing the pics; do you also use Chrome?
Currently for these cars I see as main pic the same as the last one in comments. Is it the old or the new pic?

Maybe related or not, but having slight problems replacing main pictures in Between The Lines as I find better captures from later eps. Doing everything I normally do, and all stages appear to work through normally except that the older picture stays stubbornly in place. First go was for the Saab - several attempts failed. Tried both direct upload and indirect (posting it as a comment picture, which was accepted without problem, and then copying that reference into main upload page). Also tried dropping an unrelated picture in instead (used the series title picture as a test), which eventually showed. Then retried the Saab picture I wanted, which gave the odd result of showing in the edit function picture to drop the box onto and on the main series page, but not on the actual page. But when I switched on again today, the picture I wanted was presented, so problem had resolved itself. (I'd also tried making a couple of dummy pages and switching pictures around, and they worked fine).

Now today I'm trying to replace main on the police 405 - same problem again - can't get rid of the old picture.

Any ideas??

Some had thousands ("untitled" or "1")
That's when I added a check on the file size in addition of comparing the contents: if the site had to check the contents of 1000 files with the same name to see if it already exists, it takes time. Now it compares size, if the file has the same size only then it compares the contents.

Thanks for the information, Antoine

I would probably wanted to practice to play it safe for now

I recently celebrated my 100th duplicate! http://pics.imcdb.org/1987/title1.100.jpg

indeed, if the name already exists in the user's folder it checks the contents of the file:
- exact same content? then it returns the same link as the old one, preventing having duplicates
- another file with same name? a number is appended to the name of the new file, to avoid mixing the new and the old

Files are never overwritten.
They are deleted if not used in a comment anywhere on the site ; so what is dangerous is keep for later in a text file a link to a pic that you uploaded but did not use already.
In such case the pic can be deleted (i run the cleaning function once every few months), and another pic could have re-used the name afterwards

It does.