how about 1 ID / 1 IP, can enter freely thana room 1 time every 2 hours, but downgrade drop rate from thana card... so every player have different room (privat room)
1 player, 1 room, 1 times / 2 hours....
just like on P*rfect W*rld...
have 1 privat room for 1 player / 1 party...
how lucky are you, so you can get that drop card...
Skoll>Thana, lel.
I've never tried the thana room myself so I have no idea what the issue is.
However, my opinion on the matter is how abundant it is relative to the past. I think the drop rate is too high; it should be lowered to increase its rarity, though at this point if I reconsider what I just typed, I don't think it would make any difference anyhow. Maybe remove the floating rates for thana card only?
Thana room ought to be available once per IP, once per day. That'll do the trick.