Unknown:
Macintosh model.
MacOS X version (jaguar - 10.2.x, Panther - 10.3.x, Tiger - 10.4.x).
Although I did not verify all Apple applications; but, it seems most (if not all) do included the 'Edit, Special Characters...' menu item. Some, but not many third party applications also include it.
The appearance of the 'Character Palette' floating window, by selecting the application's 'Special Characters...' menu item, is not an internal feature of that application.
Inside the '/System/Library/Components/' folder are '.component' files; which, within them are floating palette applications. Within 'CharacterPalette.component' is 'CharPaletteServer'; which, when launched produces the floating window titled 'Character Palette'.
Since 'CharPaletteServer' is independent of 'Safari'; resetting and / or quitting 'Safari', and / or clearing 'Safari's cache - should, and will, not have any affect on 'CharPaletteServer's behavior.
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With respect to 'I have also restarted the computer and it still happens. Is this Safari or an operating problem' - what are you saying?
01. Do you mean - when the Mac is turned OFF and then ON, or restarted (rebooted), 'CharPaletteServer' is automatically re-launched and the 'Character Palette' floating window reappears?
If so, launch 'System Preferences' ('/Applications/' folder), click on 'Accounts', click on 'Startup Items' (Panther - 10.3.x) or 'Login Items' (Tiger - 10.4.x) [see the reason for providing the version of System / MacOS X installed?].
Is 'CharPaletteServer' included in the right hand side list?
If so, click on 'CharPaletteServer' once, click the '-' icon button, beneath the list, and quit 'System Preferences'.
02. Or, do you mean - when the Mac is turned OFF and then ON, or restarted (rebooted), and when 'Safari' is launched - that the 'Character Palette' floating window reappears?
To possibly quit 'CharPaletteServer', should it be flashing about, launch 'Activity Monitor', click on 'CharPaletteServer', then the toolbar's 'Quit Process' icon button, and then the 'Force Quit' button of the drop down sheet.
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