It sounds like your video filter is missing. try adding your mp4codec and if you can google search for tcpmp 6 and there should be an ac3 filter and an mp4 codec filter to add via hotsync or did I get that from the r7.2 tcpmp? I can't even remember.
If you add the filters and it still isn't working it might be that the video is not encoded in a format useable by the player.
What kind of file are you playing? mp4, mp1, or avi?
You might need a proper converter. I think someone mentioned one earlier.
Still confused-- Go to
TCPMPdownload player 6.6 which will have or should have all the codecs filters you need.
Before installing this app- Delete Current tcpmp application in your unit. (I'm not sure if the one you have has all the files, there are some nice things about the newer versions, but the old one works on more video files - at least that is what I've found.)
Unzip the file
Put in the following prc codecs into your palm treo through the install tool
tcpmp.prc
tcpmp_aac_plugin.prc
tcpmp_ac3_plugin.prc
tcpmp_amr_plugin.prc
tcpmp_camera_plugin.prc
tcpmp_ffmpeg_plugin.prc
tcpmp_maktroska_plugin.prc
tcpmp_mp3_plugin.prc
tcpmp_mpc_plugin.prc
tcpmp_mp1_plugin.prc
tcpmp_mp4_plugin.prc
if you want to play .ogg files add the Ogg/Vorbis codecs.
The rest are for other players Those codecs should all work fine in your treo and play the video. I still find that my mp4 is a bit choppy. I mostly play . avi files
If interested in the different video formats please see wikipedia and search for video file formats.