I messed up somehow. I'm training my Venusaur for the EV spread 252 HP/252SDef/6 Speed. I gave my lvl 5 Bulbasuar 10 HP Ups and 10 Zincs and took it out into the big bad world, using the Exp. Share and Macho Brace to defeat the equivalent of 152 Whismur, 152 Tentacool and 6 Zubat. It was at lvl 30 when I completed this process, which is about average for me to complete EV training. But, when I went to the lady next to the Energy Guru in Slateport, she said that I haven't gotten all of my EVs yet. So, I figured I'd miscounted once or twice, went back and defeated 5 more Tentacool and 5 more Whismur. Went back and the lady told me the same thing!!! I've gone back and defeated a bunch more Tentacool and Whismur. I don't really want to go back and try more Zubat because I don't want that speed to take away any of the EVs that I want to go toward HP and SDef. I'm at a complete loss of how a 31 year old man with a college degree in information technology can be unable to count!!!!
I guess my question is: if I go back and keep battling Tentacool and Whismur, with the EVs earned after 255 just not count, or will they not be applied to the stat, but take away from the possibility of earning more EVs in another stat?
For example, if my Venusaur defeats 510 Whismur, it will only get 255 EVs. Will those extra 255 EVs that it got not count toward anything, or will they prevent me from doing my S Def training?