I have the same problem on an XP SP2 system. This is the work around I have found to work.
Open the settings, and select "TV Channels"
Load the desired channel list... DO NOT click "Apply" and leave the settings page open.
Open the Task Manager and switch to the "Process" tab, and click the "Image Name" column to sort by name
Do the following IN ORDER.
"End Process" for "VideoControl.exe" first, and then "End Process" for "PMCLoader.exe"
This should close TVCenter Pro.
Wait a few seconds and then open it again. Your Channels should be there.
If this does not work, try deleting all the channels under the "Available TV channels" column in the TVCenter Pro Settings and repeat the above steps. (You may need to close and restart TVCenter Pro after deleting channels before loading saved channels. I had tried deleting all the channels so I am not sure it will work if channels already exist.)
PS I found this out when I tried to load a different channel list than the one I desired and then later on when changing channels TVCenter Pro locked up so I had to kill the process. When it restarted the channels were there. What I have a feeling is going on is that it loads the new channels, but somewhere there is a bug displaying them in the settings, so hitting "Apply" or "Close" rewrites the existing channels, and hitting "Cancel" doesn't write the new channels. And/Or when TVCenter Pro is closed properly what ever the exiting channels are are re-written to the stick.