I too have seen the problem being described here. I bought my Wings container used, but fairly new (it had ~50 jumps on it) and I noticed that the reserve flap tuck tab would become "untucked" sometimes after doing some freeflying. Some jumps later, I had the reserve repacked, and the problem seemed to go away.
More recently, I had the reserve repacked again, and I noticed that the reserve tab started to come out again on some freefly jumps. Also, I noticed that the poptop wasn't sitting as cleanly as it could be against the rest of the reserve container- I could even see a bit of the PC fabric. So I took it back to my rigger and they opened and reseated/adjusted the reserve in the pack tray, as well as shortening the closing loop slightly.
Although I haven't put that many jumps on it yet to realistically say the problem is gone, I have not seen it since.