How do I activate Quicktime Pro

So the Pro features are still greyed out?

Try repairing permissions and re-booting your Mac, that should do it.

Open QuickTime Player and then "About QuickTime Player" menu item.
Is there a small word "Pro" on the QuickTime icon?

QuickTime Pro can't edit muxed file formats (MPEG 1 or 2 and Flash).
Use MPEG Streamclip (free) to edit your .mpg files.

I see that you have your problem resolved, but thougt maybe someone could help me with mine. I purchased Quicktime Pro, never got a confirming email. And, though the status of my order showed that I had paid AND that it was electronically delivered, it wasn't. There are no downloads. I'll keep this next part short, but after a conversation with support, being told someone will respond in 48 hours, and then it would be SHIPPED in five days, I finally asked to speak with his manager. HE confirmed it never downloaded. Gave me the keycode, which I didn't have, and explained to me what to do. And, at end of conversation kept directly me to go to the support pages. I've used Macs since the Mac Plus and can troubleshoot problems, do systems management, so I am not a novice. I do not have the symbol showing it IS Quicktime Pro. I just can't figure out if I even have what I need to do this. I have never even had to post anywhere for a problem, nor not been able to get information through support. Anybody have an idea what I can do? (I really can't believe this is Apple.)

iMac Mac OS X (10.4.9)

Quicktime Pro is not a download, it is not 'shipped within 5 days'.

What you get is a registration code by email from Apple. Enter this in your Quicktime registration window, and all the greyed out features in Quicktime will work.

Log in at the Apple Store using the account ID used in your purchase and click the link for your "Downloadable software history".
In it you'll find your registration info which can be entered in the QuickTime System Preference / Register areas.

Thank you, QuickTimeKirk AND Klaus 1,

You were both correct. I didn't receive any email at all from Apple, which is why I called. That was the first problem.

The registration code was given to me verbally by a support person, and he didn't mention any hyphens. However, the code needs hyphens after every four numbers in the series.

Previously when I entered it in the preferences, the registration did not work. However, when I followed your advice to log in and see the code under "downloadable software history," I noticed it had hyphens. I copied and pasted, and it worked! Thank you so much!

OK
Glad to hear you've got it sorted out!
Now go out and make some QuickTime content like this file of mine:
http://homepage.mac.com/kkirkster/.Public/RedneckTexasChristmas.qtl