Why on earth are you using JK2radiant?!?!
Either get 1.4 (Still a bit old, but it works better then JK2radiant), or 1.5. 1.5 came out this year, and it works A LOT better than JK2radiant.
I'm just confused where you got the idea that you should use JK2radiant in the first place...
Quake 2 player.
Real life player.