firefox3 addon doesn't get installed!!!

[sganesh]

Hi,
i am using Firefox3.when i about to install addons like NoScript,AdBlockerplus,Greasemonkey.It shows following error.
----------------------------------------------------------------------------------
Firefox could not install the file at

https://addons.mozilla.org/en-US/fir...80609.0-fx.xpi

because: Unexpected installation error
Review the Error Console log for more details.
-203
--------------------------------------------------------------------------------------------
,So no addon r installed!!.Pl Help me in fixing addon!

[Vishal Gupta]

^^ Following link might help you:

How to Fix “Unexpected Installation Error -203″ Problem While Installing Extensions and Themes in Mozilla Firefox?