There are several things that can cause this problem.

1. There is additional software running in the background. This is especially true if extra software has been installed in the player. Because any additional program takes extra resources from the player, the player can freeze if all resources are being used. To fix this problem disable all non necessary programs from running (the only programs needed for JB-199 are "startup" and "FTP server"  in the system configuration utility ( start/run/msconfig/startup )

2. The player is overheating. Especially if the player is inside a case with other players. Remove the player from the case to test for this possibility.

3. The player is going into puase mode. This would be caused if the player is receiving a signal ( the signal does not have to come from a remote, many other things can send out infrared signals) that it interprets as a puase command. When the player freezes look at the status LCD in the front of JB-199. If the status has changed from play to pause then this is your problem. Reposition the player or cover the remote reciver ( below the LCD ) with black tape to fix this problem.

3. The hard drive needs to be defragmented and checked for errors ( especially if your player is several years old ) . If you have a back up hard drive use it to test for this problem.  

4. The player has collected excessive dust over the years. With the player off and all cables unplug, remove the top cover and blow out all dust inside with a compress air cleaner. ( MAKE SURE TO WAIT 15 MINUTES AFTER CLEANING THE UNIT TO TURN IT ON )