In Jedi Academy w/ 1.01 patch:
When I join a server, my first life works fine. I see everyone as the character that they have selected. After my first death, everyone suddenly changes to my character. If I select a new character, everyone changes to that one after my next death. I have tried re-installing with no luck. Everything else seems to work fine.

im not sure about jedi academy but in quake 3(same engine) in options there is a force player models option. Could this be the case?

Yes, there is a Force Player Models option in JA. Go to your setup and turn it off.

Try pressing TAB when this happens, it is sometimes just a bug that happens for some reason and if you press TAB is should fix itself.