Bugs #1,2: known, random, weird, trying to fix. #3: not explored & not known how to fix: Windows XP also doesn't display all 32-bit .ico files, only some of them. #4: this bug happens because when 32-bit & non-32 bit image is composited, it is impossible to distinguish what result is. Render may be either with weird arrow or weird arrow and no image at all. Don't know what to do either. Other than that, i'll try to fix #1-#2, and also add 32-bit icons in taskbar at least.