OK so I get this coin (in a new ANACS slab) and it looks to me as if the slab has been cracked and resealed, but maybe they are all like this. I'll take some pictures, but in general are the slab edges clear or are there cloudy spots. If you run your fingers along the edges, is it smooth or rough and bumpy? What's odd is that it's just a 1938-D Buffalo and the coin looks MS-66 (the grade given) or very, very close (which wouldn't make sense). Maybe I'm not too hot on grading MS-66 though but besides that, the slab looks odd, but it's the first newer one I've seen. Maybe they all look like this.
Hmmmm... this current ebay auction seems to have a slab that looks the same, but some pictured do not have this (and are clear all the way around).
I have some new ANACS slabs from when they just switched, and some new ones from recent submissions. None of the edges look like that. I'd be a bit suspicious.
Can you still take them apart with your fingers? Maybe that glued one was a stop gap while they were trying to cure the problem. This thread talks about the early on problems of the new slab. http://www.cointalk.org/showthread.php?t=14280
I'm not sure it is glue or if it's the plastic melted/fused together that caused the cloudiness. I don't think it would be easy to take it apart (at least now, heh). The coin looks to be as good as other MS-66 coins I've looked at so I suppose it's OK. Just odd.
I plan to avoid buying any coin in a new ANACS slab. I own quite a few coins in the old slabs, and it's a shame this happened because I liked the service. It's just too risky to buy at this point.