QT Pro won't allow "subtitles" to open.

iMac, OSX 10.8.5

I bought QuickTime Pro from the Apple Store, received their registration code in my email, copied and pasted both the user name and the code into my QuickTime 7 registration panel, checked and it was identical. It took, sorta. The QT Pro icon appeared on the registration panel but while it was promised, it DID NOT activate any of the greyed out "options". In my computer, QT 7 and QT Pro are identical.

In particular, I need to turn On "Subtitles", which stubbornly shows only a grayed--out Off.

Three very nice/patient Apple Support Team members, with screen sharing, explored my computer, all assuring me that though the Pro icon appears only in the registration pane, the Pro functions have been turned on. QuickTime 7.6.6 now shows in "get info"

I only bought QuickTime 7 and QuickTime Pro for the subtitle feature to add text to QuickTime movie's, I cannot turn it on and I need it very much.

Thanking all of you in advance.

Bob