I would really appreciate your help
You may not like it, but my advice is to just not use Quicktime. Macs suck. Quicktime is a Mac thing. Just never use it. Don't even install it.
ah! ah! yes good idea but... around me everybody is using quicktime it seems...
Hate to bring out this old gem but, if everyone around you is jumping off a bridge onto a concrete highway, you gonna do that to?
Forget what others do, you do the right thing. And the right thing is to avoid all things Mac.
It's a PC world we're livin' in. Mac folks need to get used to it. And whenever you see someone else doing the wrong thing by using Quicktime, or even (God forbid) actually using a Mac, well...you just go ahead and straighten them out. Bring 'em back into the light. And we can all live in a happy world where every hard drive is formatted as NTFS and everyone's files work on everyone else's computer, just as it should be.
And then the real battle can begin - getting rid of all those Pepsi drinkers!
Unfortunately or maybe otherwise...it's not entirely a PC world as Jim sees it because Jims world revolves around his comfortable "known world" of DV and I-frame media. I would suggest his clients are not as demanding as my own who have moved forward from SD and DV even if they were ever there in the first place.
I integrate my suites with professional post productions houses and they all use Macs in the processes that I require... so it becomes part of my workflow by neccessity. (FWIW : broadcast television brand commercials shot HD on 35mm film or HD file-based media workflows)
For the record. I am not a fan of MACs myself but what ever..I need to get the job done so I get on a do it...
I also integrate with professional creative artists on MACs and PCs. There are no issues in this regard that can not be easily managed.
I have no problems exporting HD Qt (.mov) from my PC in AME.
There are no issues of quality or process (apart from the know "gamma thing" and I can accomodate that in my own export process).
I have no idea why you can not export to QT but if you need to... you need to ..so you need to do a few experiments to get to the base of the issue.
Could be hardware, software or operator error...
Don't try to encode to QT from PR. Jim is right. An alternative could be to use Sorenson or QT Pro and encode with the Animation codec.