I've just tried it in IE again, and it froze again. May I see your page with the working form?

I can answer my own question now. The answer seems to be "yes". plupload converted 3 sample CMYK jpg images to RBG color space, and the results were good, in my opinion. (There didn't seem to a difference in colors.)

I saw it. Firstly, that article is too deficient in details. Secondly, here's what it says:

I wanted, for example, to change text in the queue widget, so doing that "before the uploader is initialized" didn't make sense, yet this is exactly where it worked.

Still, this area is confusing. Good docs would help, but they don't exist. People have been inquiring about basic things that should've been covered by documentation.

Now I feel I might be interpreted as an ungrateful SOB. I am not. I am thankful for this software and that it's free. Good docs would help, though

Thanks for the explanation, Leandro. But what is a "section" here? Is it a JavaScript concept or something plupload devs have come up with?

It would be good if somebody wrote a set of documentation articles explaining things like that.

May I suggest a different way to approach this? Why don't you use AJAX to do the form's validation, and upload the entire form only its input is valid?

In their example at http://www.plupload.com/example_queuewidget.php they show how upload files when the form's submit button is clicked. You might even want to remove the Start upload button.

If you decide to remove the button, here's the code inside the initial call of pluploadQueue():

preinit: {
            PostInit: function(up) {
                $(".plupload_start").hide();
            }
        }