rem: this.appLauncher.saveToDisk( null, dontAskNextTime ); 
add: try { this.appLauncher.saveToDisk( null, dontAskNextTime ); } catch (exception) { } 
context:     onOK : function () {        // Get boolean switch from checkbox.        var dontAskNextTime = !document.getElementById( "alwaysAskMe" ).checked;            if ( document.getElementById( "runApp" ).checked ) {            // Update preferred action if the user chose an app.            if ( this.userChoseApp ) {                this.appLauncher.MIMEInfo.preferredAction = this.nsIHelperAppLauncher.useHelperApp;            }            this.appLauncher.launchWithApplication( this.chosenApp, dontAskNextTime );        } else {            this.appLauncher.MIMEInfo.preferredAction = this.nsIHelperAppLauncher.saveToDisk;            this.appLauncher.saveToDisk( null, dontAskNextTime );        }            window.close();    },
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/389461c9d5b21c81c31e44f8d5888ab492ee4d92/helperAppLauncher.js/buggy/xpfe/components/ucth/resources/helperAppLauncher.js