I have Core .72 so i can play mpeg4's and pocket Divx for divx and xvid. I downloaded a .mp4 and it said to use either Core or a divx player and I can't get either to play. What could I be doing wrong? I also am able to play other of both.

hmm..... maybe i am not being specific enough. I have a movie that I downloaded from here and it will not play. It is a .mp4. It says to use either core media player or any divix player. I have both latest copy's and the movie will not play. What are some known issues that can cause this?

Did you go into "File Associations" within the "Preferences" of the software to make sure it recognizes the files you are trying play?

With TCPMP and Core,... not all "File Associations" are checked when you install the software at first.