ithey are really weird, and I think it has something to do with sky chase. back when I played alot it was possible to submit scores for tails on sky chase 1 & 2, but now they are not on the rankings and it is impossible to submit a score to them, BUT if you click on sonic's sky chase rankings you can get to the tails rankings, so they are still there and they are causing unfair advantages to the rankings.
for example S3k is ranked 32nd for total tails points, when he could easily be higher, and yoshifan is 16th when he would probably be near first, and the reason they are ranked so low is cause they CANNOT submit a Sky chase 1/2 tails score, but the people that played before you "removed" (??) them could, so they have a unfair advantage and you should either make sure its finally removed completely, or bring it back, I dunno what the intentions were but I assume it was supposed to be removed, which seems logical since its the same thing as sonic's, but its still technically there for some reason so you gotta finish the job!
http://www.soniccenter.org/rankings/sonic_adventure_dx/scores/sky_chase_1/tailssee?
whats even weirder is, I (do) have submissions for both of tails sky chase and my total score should be 91,550, but its only 56,700 on the rankings (as it SHOULD be without the tail's skychase rankings) but F-Man, marth and alot of other people have total scores that include both of tail's sky chase.. so theres a big wtf factor going on that some people keep scores some like me lose it.. I really don't care at all either way about mine, but its unfair for the new people that can't submit AT ALL