There is a read-only thread in this forum that was not resolved on this topic, but I too can confirm that Ghost 15 does not appear to be backing up Windows 7 Media Center TV recordings (.wtv) in the My Computer Backup use case. I've looked into my backup files, and the directory they are stored in \Users\Public\Recorded TV is in the backup, but the .wtv contained therein are not.
I can create a File and Folder backup that seems to back up the files, but the My Computer backup doesn't copy them? Anyone else seeing this issue?