If it's your server then most likely you don't have your skillcaps changed. If you want to make sure though, you can jsut re-download the binaries for EQEMu from
SourceFORGE.net.
Typically having a hacked char is done by running a client program. The EQ game client then sends "bad data" to the server which it doesn't know to ignore. For example, I get a program that can tell EQ that "I'm supposed to have 1000 HP at level 1!" and the server will just say "Uh... OK!" and give it to me.
To my knowledge, there's nothing you can do to really prevent someone from hacking a character except watch the DB for strange instances like those you've been seeing. Then, just talk to the person the next time you see 'em online and, if necessary, ban 'em. :twisted: