User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1) Gecko/20061010 Firefox/2.0 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1) Gecko/20061010 Firefox/2.0 As documentation say: http://www.xulplanet.com/references/elemref/ref_tab.html#attr_disabled The element will still respond to mouse events [when disabled]. IMO this is wrong and should be changed, because by disabling the tab author wants to forbid user switching on a given tab with any means, obviously including a mouse. Reproducible: Always Steps to Reproduce: 1. Open the attached example file. 2. Try switching disabled tabs with mouse click. Actual Results: Tabs are switches as they're not disabled. Expected Results: Mouse clicks on disabled tabs should produce no result. Tested on WinXP (see build identifier) and MacOS X with Firefox 2.0.

Looks like it only affects remote XUL with no chrome permissions, throwing a bunch of following errors to Error Console: Error: [Exception... "'Permission denied to get property XULElement.disabled' when calling method: [nsIDOMXULControlElement::disabled]" nsresult: "0x8057001e (NS_ERROR_XPC_JS_THREW_STRING)" location: "JS frame :: chrome://global/content/bindings/tabbox.xml :: selectNewTab :: line 353" data: no] Source File: chrome://global/content/bindings/tabbox.xml Line: 353

*** This bug has been marked as a duplicate of 106387 ***