Because PowerDVD Ultra v7, or v6 does contain some codecs that does not exist in ULTRA 8 or 9 version.
You need this: HD 264 Pack ( google it), this one contain all you've need...
Shame Cyberlink...shame of you....
WHen you install HD 264 Pack you see HD codecs ... HD codecs must exist in v8 or v9 of PowerDVD but for some reson Cyberlink decide to cripple PowerDVD Ultra....
Now ULTRA DOES NOT CONTAIN HD CODECS, for use with digital tv on christv, sagetv, beyondtv, etc.