Did Apple Script change - upgraded Snow Leopard Mavericks

Question

I used to use below script to toggle sound output (assigned to function key) in Snow Leopard.
Upgraded to Mavericks few weeks ago and wanted to use that script again, but keep on getting error -1728 as displayed hereafter, anyone out there to tell me what I should do to make it work in Mavericks?
Thx,
Laerg1
Here's the full script:
--This script toggles between two audio outputs in the "Sound" pane in "System Preferences.
--USES GUI SCRIPTING - "ENABLE ASSISTIVE DEVICES" OPTION MUST BE CHECKED IN "UNIVERSAL ACCESS" PREFERENCE PANE
--Adapted from script written by Corey Menscher for toggling outputs using Salling Erickson Clicker
tell application "System Preferences"
    activate
end tell
tell application "System Events"
    tell application process "System Preferences"
        set frontmost to true
        click menu item "Sound" of menu "View" of menu bar 1
        if my wait4window("Sound") is false then return false
        tell window "Sound"
            tell tab group 1
                tell radio button "Output"
                    click
                end tell
                (* You can add your own audio output descriptive text, such as "iMic USB Audio", in the next section. *)
                if (selected of row 2 of table 1 of scroll area 1) then
                    set selected of row 1 of table 1 of scroll area 1 to true
                else
                    set selected of row 2 of table 1 of scroll area 1 to true
                end if
            end tell
        end tell
    end tell
end tell
tell application "System Preferences" to quit
on wait4window(this_title)
    tell application "System Events"
        tell process "System Preferences"
            repeat with i from 1 to 60
                if the name of window 1 is this_title then return true
                delay 1
            end repeat
        end tell
    end tell
    return false
end wait4window

Answer 1

Let's double-check the amount of RAM in that machine. Click the Apple logo in the upper left corner & choose About This Mac. In the window that comes up, what's listed for RAM?
That machine will run Snow Leopard very nicely with 2GB of RAM. For it to run Mavericks, I would upgrade it to at least 4GB or more if it can handle it.
If I was in your position, I would run Snow Leopard for a while and see how well it serves you. If you want to upgrade, my  personal opinion would be to go to Mountain Lion, rather than Mavericks, but that is simply because I found that Mavericks slowed one of my machines to a crawl and was not pleased with the performance. Went back to Mountain Lion and it's humming along.
~Lyssa