Okay so I had just traded in my Bark Modules for a pulsar.
I had another 2* pulsar sitting in my inv that I had also traded Bark Mods for a few days earlier.
Both of them have no heat and no uvs, meaning exactly the same stats.
I went into the ATH and equipped both of them to derp around a bit, and I found something interesting.
The game wouldn't let me do weapon switch when I had both equipped.
I bought two beast bashers from the vendor to test if it would have the same result.
Same thing, no weapon switchy for me.
I then equipped the free uv'd beast basher the tutorial missions give you, and found that I could switch them.
So what's the deal? If the weapons are identical the game thinks they are the same weapon?

I haven't tried this yet, but if I were to heat both my pulsars up at the same time, would this bug persist?