This can be caused by corrupted cookies or cookies that are blocked (check the permissions on the about:permissions page).

Clear the cache and cookies only from websites that cause problems.

"Clear the Cache":

• Firefox/Tools > Options > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Firefox/Tools > Options > Privacy > Cookies: "Show Cookies"

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

• Do NOT click the Reset button on the Safe Mode start window.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

There's definitely something going badly wrong here. I can add an item to the cart and have it missing later, and I can delete an item from the cart and have it back later. Since the cart is maintained on the server, and the change shows as having worked at the time it was made, this makes no sense. I think you need to contact your cart provider for support. Maybe some others reluctant to upgrade have worked out a solution.

As an aside, the Browser Console shows a number of requests for an HTML page with the referrer being your style sheet. That doesn't really make sense to me, and could indicate that there was a syntax change which expects a file parameter. If you use older Portable versions of Firefox to test, perhaps you can figure out when that started, and then consult MDN on what changed.

http://sourceforge.net/projects/portableapps/files/Mozilla%20Firefox%2C%20Portable%20Ed./

You'll notice links at the bottom of this page for developer-oriented release notes for older versions of Firefox: https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/26

By the way, updating the quantity in the cart works perfectly, so you can delete an item by setting the quantity to zero. But this certainly doesn't help with adding an item...

Hi Cor-el

Yes I was really hoping it was a local issue - so I tried all your suggestions and it has not helped. Thank you for your time.

Hi, jscher2000,

I am not the only one perplexed - glad (although not) that someone else gets the same results. So that can rule out local issues at least. Yes scoured forums for old hands still using j1.5 and vm1 - but this issue has only just come to light - seemingly after FF upgrade so not finding anything of great help right now.

I did find some with similar issues - suggesting caching issues - did all I could to eliminate those. Firebug reports an error but separate from this one and can be ignored.

Not ideal but I believe I need to backdate FF to an older version to see if the problem still exists - narrow it down, that way at least.

The filter (Cherry Picker) that is on the site was worked on at the same time this issue arose as was a few back-end code changes adding a new print column to merchant order form) I struggle to see the connection but maybe this is it.

I disabled all the Cherry Picker filter options module - removed all associations and still the problem persists - it has worked perfectly with no issues.

So a backdated FF will be next step.

Thanks for the help so far - i'll post again when I have more info.

Scott

Update:

Despite backdating FF to version 25 and even older 3.6.28

The issue still remains.

FF update is now seemingly not the issue - it is something else.

All other browsers on PC'S work as does FF on my android phone work perfectly.

Changes I made to the site, I backdated to when it did work - no change to basket /checkout issue - it remembers some and deletes others - very unstable

I can now only put this down to a FF caching issue I can't resolve. I am totally out of ideas.

So if anyone has further suggestions I would be grateful to receive them.

Thank you.

Scott