HI,
I have my iBookG4 here running v10.4.11 and Safari 4.1.
When I Ctrl click a tab I see the: Close Tab
Perhaps your Safari .plist file is corrupted. Try this...
Go to the Safari Menu Bar, click Safari/Preferences. Make note of all the preferences under each tab. Quit Safari. Now go to ~/Library/Preferences and move this file
com.apple.safari.plist to the Desktop.
Relaunch Safari and see if that makes a difference. If not, move the .plist file back to the Preferences folder. If Safari functions as it should, move that .plist file to the Trash.
If that doesn't make a difference, from your Safari Menu Bar click Safari/Empty Cache. Relaunch Safari and try closing a tab again.
🙂