Click and hover events only trigger on part of an input field in IE8

I have encountered an issue where IE8 ignored click and hover events on an input field the background of which was transparent. The clue that helped me solve this issue was that the events were triggered without any problems in the area of the input field where it contained some text. I remembered that I encountered a similar issue before, and indeed, using a transparent image as the background instead of "background:transparent none" fixed the problem.