Lately some users (including me) had a problems with uploading files that have .png extension.
According to discussion, in this image: http://e-shuushuu.net/image/513011/, problem should be fixed. It seems that something messes up again, though.
Unfortunately, I do not observe enough, if other users in past few days had any problems while uploading, but I actually had.
http://e-shuushuu.net/image/515510/
http://e-shuushuu.net/image/515515/
http://e-shuushuu.net/image/517608/
Following Kage's advice, I decided to make this forum topic.

If this is some strange bug's case, I hope this will be fixed soon ;-;

Hmm, could you upload these failing PNG somewhere else( like the forum)? I would like to check them, and the admin too I believe.

Also, which browser are you using? Any particular extension on it?

I can give you links to these images.
http://danbooru.donmai.us/post/show/874 ... ynike-bad_ - First two pictures (I tried to upload this image twice, but with the same effect). It was deleted from pixiv, unfortunately, otherwise I would give you link to pixiv.
http://www.pixiv.net/member_illust.php? ... 259&page=0 - Third picture.

I use Mozilla Firefox from... years. I did not added any extensions to it lately and before I do not have problems with .png. Most probably, it is not my browser's fault.

Impossible for me to test uploading, binary compare works... I suppose I will just leave this to the admin.