Which version of the game are you using? If you aren't on version 8.0.0.13, please use the following patch and see if you continue to have trouble:
http://www.ootpdevelopments.com/boar...d.php?t=158299
Which operating system are you using? How much RAM does your computer have and how much free hard drive space?
What type of league are you running when seeing these freeze-up problems? Real life players? Fictional ones?