Man! Mods have come a long way. I never got a "don't abuse product" warning, and I'm sure I did, plenty. That said, it's vaguely ominous sounding to me. The two possibilites sound achievable to me. If your tank is fine, get t off there ASAP (have you tried screwing the tank into another mod to at least see whether it's your mod or the tank? If you have a B&M store with an electronics expert, you might take it there. BUT, if it's the mod, you could get a spinning tank merely because the tank itself can't form a good connection with the mod? Either way, I'd get your mod looked at unless you're pretty mechanically minded and want to try the suggestions above.
Anna