I found this bug in Flash 8, so I just downloaded CS5.5 trial and I see the same problem.
When I increase the image export resolution to get a larger image, at one point the lower section of the image became white (the image has the appropriate size but the content is not rendered in the lower section). As bigger is the image, larger is the white fraction. The amount of useful pixels always stay around 10 or 13 megapixels. Here some examples:
Original image was 3375x6710 pixels in the left one and 2625x5219 en the right one. Any idea to solve this?? Can anyone reproduce this problem?
That article is regarding the size of the bitmaps you can put INSIDE the project, and the issue I'm experiencing is regarding the size of the output when you use the "Export image" function.
Actually I got the same problem even if I delete all bitmaps from the stage and try to export only the vector features (lines, text, etc...).
I can't see clearly how the limit explained in that article could be related to a limit of exported images.
As example, the following image shows the same issue, but this time of a project with only vector data, no bitmaps at all, you can see how the rendering is truncated.
the same limits apply to bitmap export.
when exporting an fxg file, i don't see the same limitations and can export and import 5700+ x 5300+ vector graphics.