In gametab.scar:
Simba Code:
{*******************************************************************************
function GetLobbyTab: Integer;
By: Bionicle1800
Description: Gets current lobby tab.
*******************************************************************************}
function GetLobbyTab: Integer;
var
tx, x, y : Integer;
begin
tx := 63;
for Result := 1 to 5 do
begin
if FindColorTolerance(x, y, 3093560, tx, 21, (tx + 122), 49, 2) then
Exit;
IncEx(tx, 122);
end;
Result := -1;
end;
And in login.scar:
Simba Code:
//line 659:
if (LobbyScreen) then
MouseBox(256, 442, 507, 478, 1); //Button
I guess it'll be fixed soon enough but I needed this fast so here you go if you do too 
I don't think that switching lobby tabs works yet.
And no, this is probably not the most efficient way to do this.