Script removes the last 2 indexes in a table but only 1 every other time?

I'm making a private message/notification system for fun. I have most everything down, but there is one bug I haven't been able to iron out. My system works like this: I type a command in the command bar which goes to a global function that takes a variable form the command and turns it into the text of a Message. That Message is put in the player object.

I just realized this is going to take a while to type, I'll just post the code and hope you understand it. If you need help deciphering my messy code just ask for an explanation.

player = game.Players.LocalPlayer
gui = player.PlayerGui["Messages"].TextLabel    
iu = false
waiting = {"Don't delete me ;_;"}
deb = false
deb2 = false
removable = true
function tweenin(text)
    iu = true
    gui.Text = text
    gui:TweenPosition(UDim2.new(0.25, 0, .125, 0), "Out", "Quad", 2, false)
end

function tweenout()
    gui:TweenPosition(UDim2.new(0.25, 0, -1, 0), "Out", "Quad", 2, false, function()
        iu = false
    end)
end

player.ChildAdded:connect(function(mes)
    if mes:IsA("Message") then
        print("Message recieved")
        if not iu then
            print("not iu")
            tweenin(mes.Text)
            gui.button.MouseButton1Click:connect(function()
                deb = true
                tweenout()
                mes:Destroy()
                wait(.5)
                deb = false
            end)
        else
            print("iu")
            table.insert(waiting, 1, mes.Text)
            repeat wait(1) until iu == false
            print(table.concat (waiting, ' '))
            print(waiting[1].." going")
            tweenin(waiting[1]) 
            gui.button.MouseButton1Click:connect(function()
                deb2 = true             
                tweenout()
                if removable then
                    print("removing") -- When it removes two things from the table this prints once, just like every other time.
                    table.remove(waiting, 1) -- The only place that anything is ever removed from a table. 
                    print("removed") -- same as above, only prints once
                end 
                removable = false
                mes:Destroy()
                repeat wait() until not iu
                wait(0.5)
                deb2 = false
                removable = true
            end)        
        end 
    end
end)

Here's the output:

Message recieved
not iu -- first message starts without having to wait
Message recieved
iu -- is waiting
Message recieved
iu -- is waiting
Message recieved
iu -- is waiting
Gold 300, Experiance 5, Level 1, Don't delete me ;_; -- list of waiting message
Gold 300 going -- is going to be next
removing -- whichever just went gets removed
removed
Experiance 5, Level 1, Don't delete me ;_;
Experiance 5 going
removing
removed
Level 1, Don't delete me ;_;
Level 1 going 
removing -- This only prints once, but the last index in the table (don't delete me) disappears without a trace....
removed

Thanks for any information you can give me, LightArceus