I have joined with 1.8 and 1.7 packs and vanilla instances multiple times while setting up and after and never had that issue, there's also no reason for it to do that as item id's are stuck in vanilla items via numbers and name
Those stands are having fun there, in any case try relaunching if your playing modded then sometimes the id's of items can load wrong, I know it sounds stupid but it's happened before like iron turning to sand for me
i know that im cursed.. but after closed the launcher the armor stands are still there[DOUBLEPOST=1452378974][/DOUBLEPOST]and even there:
Actually, that makes PERFECT sense, as their still listed as entities in 1.7, and can be named to look like that, but the hub is 1.7/1.8 compatible so you get both, it's actually a pretty nice idea, not sure why i never thought of that being how it's done before...