Glass panes and iron bars connect to barrier blocks

    public final boolean canPaneConnectToBlock(Block blockIn)
    {
    	//added "blockIn == Blocks.BARRIER ? false : "
        return blockIn == Blocks.BARRIER ? false : blockIn.getDefaultState().isFullCube() || blockIn == this || blockIn == Blocks.GLASS || blockIn == Blocks.STAINED_GLASS || blockIn == Blocks.STAINED_GLASS_PANE || blockIn instanceof BlockPane;
    }