Failure of changes to a logo.gif image to appear on a Windows 7 web site

[lewisasding]

Good morning everyone, I have a question which I hope may be answered on this forum.

I changed the logo.gif to reflect changes in our Shipping charges. I did this via FTP and overwrote the changed gif file back into its classic and customised files.

Re-opening the browser I found the OLD gif file displaying the original image. Over the next hour I shut down the computer and re-booted several times without any success. Several hours later I still found the same OLD images.

I downloaded the NEW files via FTP and opened them and checked and yes they were the changed files.

I was advised that when changing the content of an image to ‘RENAME’ the original file on the 'web host' after downloading a COPY. The COPY retains the original name, and of course when you upload back into the Host it does not have to overwrite the original.
I was also instructed to press CTRL+F5 after the changes had been completed. I have no knowledge of why this is necessary, but it worked and the NEW gif is now displayed on our website.

However there is more, my wife has an iPad 4, and she uses it to process orders from customers; her browser when used to access our web site showed the OLD gif; even after the Windows 7 browser used the NEW image. It took several more hours before we saw the NEW image on our iPad.

Can any one please help with an explanation of what is going on here?
Where has the ‘ghost’ copy been stored? More worrying is, if my wife’s iPad fails to change then what about all the other iPad’s out there that have had access to our site.
Again thanks for any help and advice given to me

[stevesh]

My guess is that you would have seen the original changes immediately had you done the CTRL F5 thing then. ( In Windows, CTRL F5 forces a page refresh without using what's in the browser cache.) It's also possible that your ISP is caching pages at its servers. If you have access to a different ISP, you could test that. Whatever the source, I'd say it's almost certainly a caching issue.

[lewisasding]

Thanks for your prompt reply. Much appreciated.

My guess is that you would have seen the original changes immediately had you done the CTRL F5 thing then. ( In Windows, CTRL F5 forces a page refresh without using what's in the browser cache.) It's also possible that your ISP is caching pages at its servers. If you have access to a different ISP, you could test that. Whatever the source, I'd say it's almost certainly a caching issue.