There's a bug in Firefox (and Thunderbird, I'm told) which means if you drag & drop an image from the browser to Opus (and other programs) you will end up with a zero byte empty file.
I thought I'd mention the problem here in case anyone searches for the issue thinking it's an Opus problem. It affects Opus but the bug is definitely in Firefox.
I have just reported the bug to Mozilla.org since it didn't look like anybody else had reported it:
OK Nudel,
I haven't verified your results.
I believe you.
It is bothering me though that I see a somewhat similar thing using IE7.
Dragging and dropping an image from an ancient web site of mine as viewed in IE7 works fine in Explorer, but doesn't work at all in DOpus.
For instance, try this page.
Perhaps I'm off topic though.
You did mention a zero byte file.
Please just delete this if it's not relevant.
There is some kind of problem doing the same thing using IE but I'm not sure what's behind it.
On Vista the first time I tried I got a security prompt asking if I wanted to run something to do with Opus, but then nothing happened. After being prompted a couple of times I haven't been prompted again and it looks like the drop is silently ignored each time. If I drop on Explorer instead then I also get a prompt, but it seems to come from Explorer rather than IE.
I suspect the drop data that IE is providing is in a format that Opus doesn't understand, so nothing happens. I might be wrong, though.
I don't think the two are the same issue, but had you not pointed out the problem with IE then I wouldn't have noticed it (I don't use IE, except to test my pages and then waste 10 hours of my life making them render properly in IE, hehehe), so it's good to have it pointed out! I'll take a look in more detail when I get time.
The Firefox problem happens for me on both XP and Vista.
The IE7 problem only happens on Vista, and looks like it's to do with the way IE7 runs under a "low integrity" process which can't talk directly to the program it drops on.
If you want to try doing exactly what I did to get the zero-byte files from Firefox, click on this link and then drag the image to an Opus window.
If it's strictly a Firefox problem, then why can I drag-n-drop from it to Windows Explorer just fine? (Firefox is unaware of the recipient of the message; it just dispatches it to the OS.)
Also, it seems that the bug does affect Explorer, but only for large files.
It is 100% Firefox's fault and, as much as I love the browser in general, it's doing something really stupid when it comes to drag & drop to other programs.