To put it simply, when both Charset Block Carrying and Better Placement are installed together the right click event gets very sensitive, if you shift click to pick a block up you're more than likely going to place it back down immediately, this being because Better Placement allows instantaneous block placing, you'd probably need to set up some event that temporarily disables the mods functionality.

Sorry for the late response, no I haven't been using Carry On, I chose against using it over preferring the Charset brand
I am most definitely using Charset Block Carrying

That's weird. My Block Carrying uses shift-middle click to pick blocks up.

Oh really? I find that odd given the fact I've been using right click this entire time.

Have you been using Carry On? That mod uses shift-right-click.