Sorry, should have added more details.

The Standard Uploader 'browse' button does not respond when clicked. If you keep clicking incessantly it will eventually open but once you choose the picture to upload it will freeze and the firefox browser will crash and close.

The Basic Uploader works fine.

In order to uninstall a possibly unwanted extension, please do the following:

1. Click the menu button and choose Add-ons.
2. Once the Add-on Manager has opened in a new tab, click the Extensions button on the left side of the window.
3. You should now see a list of your installed extensions on the right side together with buttons on the right side of each extension.
4. To remove an extension from Firefox, simply click the Remove button. You should see a message that informs you about the successful removal of the add-on.
5. Note that some add-ons require a Firefox restart to be removed completely. To perform a Firefox restart after the add-on removal, click the Restart now link in the message.

You can find further information about uninstalling extensions in the following articles:

• Disable or remove Add-ons

• Remove a toolbar that has taken over your Firefox search or home page

Thank you for the reply

I've checked Extensions and there are two, both are disabled.

Is there a way of working out which extension or plugin is causing the probem? other than just deleting all of them...